itz-youssef/Car-wash-system

system simulates a real car-wash flow: cars arrive and wait in a fixed-size queue, pumps pick them up as soon as they’re available, and semaphores coordinate everything so cars only enter when there’s space and pumps work only when a car is ready—creating a clean, thread-safe producer-consumer cycle.

Language: Java - Size: 4.88 KB - Last synced at: 1 day ago - Pushed at: 1 day ago - Stars: 0 - Forks: 0

cmelnu/thunderos

ThunderOS is a lightweight RISC-V operating system designed for AI acceleration and educational experimentation.

Language: C - Size: 532 KB - Last synced at: 2 days ago - Pushed at: 2 days ago - Stars: 0 - Forks: 0

hoqueeprobal/Operating-System-Lab

This repository is a collection of Bash scripts and concepts I learned during my Operating System Lab

Language: Shell - Size: 6.65 MB - Last synced at: 2 days ago - Pushed at: 3 days ago - Stars: 0 - Forks: 0

StjepanPoljak/raspios

A DIY operating system for the Raspberry Pi bootable from Supervisor or Hypervisor (tested on U-Boot). Featuring MMU and memory (heap) allocator.

Language: C - Size: 77.1 KB - Last synced at: 3 days ago - Pushed at: 3 days ago - Stars: 2 - Forks: 0

kguzek/coursework-wust

A repository containing coursework for the Wrocław University of Science and Technology.

Language: Java - Size: 549 KB - Last synced at: 7 days ago - Pushed at: 7 days ago - Stars: 0 - Forks: 0

MustafaAlotbah/PalmyraOS

An Educational Operating System based on x86 aiming for simplicity.

Language: C++ - Size: 1.13 MB - Last synced at: 10 days ago - Pushed at: 10 days ago - Stars: 1 - Forks: 0

cheatsnake/backend-cheats

📃 White paper for Backend developers

Size: 10 MB - Last synced at: 10 days ago - Pushed at: 10 months ago - Stars: 3,971 - Forks: 394

dreamportdev/Osdev-Notes

A book that explore how to write an Operating System from scratch

Language: Markdown - Size: 4.49 MB - Last synced at: 10 days ago - Pushed at: 10 days ago - Stars: 915 - Forks: 66

SarthakRawat-1/shogun-os

Language: C - Size: 1.76 MB - Last synced at: 19 days ago - Pushed at: 19 days ago - Stars: 4 - Forks: 0

ImShizue/HollowOs

This OS is Hollow like a famous Knight. and like me (it mean it'll be minimal) | Moved into : github.com/Auri-OS

Language: Shell - Size: 435 KB - Last synced at: 21 days ago - Pushed at: about 1 month ago - Stars: 11 - Forks: 0

cybersecurity-dev/awesome-os-development

Awesome OS Development

Size: 25.4 KB - Last synced at: 14 days ago - Pushed at: 24 days ago - Stars: 1 - Forks: 0

abdullahejazjanjua/operating_system

This repository contains the assignments, lab tasks and independent practice for OS that I have done during my Bachelor's at GIKI.

Language: C - Size: 129 KB - Last synced at: 26 days ago - Pushed at: 26 days ago - Stars: 0 - Forks: 0

dreamos82/Dreamos64

My experiments with osdev... again

Language: C - Size: 570 KB - Last synced at: about 1 month ago - Pushed at: about 1 month ago - Stars: 187 - Forks: 12

scottfitzhugh/scottos

A minimalist operating system written in Rust that aims to be fully POSIX-compliant while maintaining simplicity and clarity in its design. This OS is built from scratch using modern systems programming practices and leverages Rust's memory safety features to prevent common OS vulnerabilities.

Language: Rust - Size: 80.1 KB - Last synced at: about 1 month ago - Pushed at: about 1 month ago - Stars: 1 - Forks: 0

Mark-Walen/mark-walen.github.io

My study log

Language: HTML - Size: 69.3 MB - Last synced at: about 2 months ago - Pushed at: about 2 months ago - Stars: 0 - Forks: 0

LohithSridhar/Nova

Nova - A simple (for now) educational OS built by me, for me.

Language: C - Size: 1.49 MB - Last synced at: 2 months ago - Pushed at: 2 months ago - Stars: 0 - Forks: 0

openSUSE/lessons

This project is a collaborative effort for designing and preparing lesson plans for teachers, home educators, students and self-learners. The lesson plans focus on segments of open-source software development, culture and contribution.

Size: 612 KB - Last synced at: 29 days ago - Pushed at: 29 days ago - Stars: 9 - Forks: 2

PiperLiu/CS-courses-notes

✨终生持续更新✨ 计算机基础自学笔记/心得/实验/资源汇总；课程：数据结构、操作系统（MIT6.S081）、分布式系统（MIT6.824）等

Language: Jupyter Notebook - Size: 452 MB - Last synced at: 3 months ago - Pushed at: 3 months ago - Stars: 543 - Forks: 72

KlondikeDev/WingspanOS

Language: C - Size: 96.7 KB - Last synced at: 3 months ago - Pushed at: 3 months ago - Stars: 1 - Forks: 0

caden-maxwell/uefi-dev

A just-for-fun repository to expand my knowledge in UEFI development.

Language: C - Size: 5.21 MB - Last synced at: 3 months ago - Pushed at: 3 months ago - Stars: 0 - Forks: 0

leo-aa88/primus-os

A simple bare-bones 32-bit operating system written in Assembly x86 and C for educational purposes

Language: C - Size: 67.2 MB - Last synced at: 3 months ago - Pushed at: about 2 years ago - Stars: 50 - Forks: 11

AlexDev404/Sapphire

An x86 Operating System in (Formerly: Rust) C/C++ and Assembly

Language: C - Size: 2.47 MB - Last synced at: 4 months ago - Pushed at: 4 months ago - Stars: 2 - Forks: 0

chetankamani/operating-system

A complete resource hub for Operating System course including notes, labs, and study materials.

Size: 2.64 MB - Last synced at: 4 months ago - Pushed at: 4 months ago - Stars: 14 - Forks: 0

AndyKolski/tOS

A simple operating system built from the ground up

Language: C - Size: 979 KB - Last synced at: 4 months ago - Pushed at: 4 months ago - Stars: 0 - Forks: 0

SpeedyCraftah/speedy-os

X86 operating system attempt from scratch written with C, C++ and Assembly.

Language: C - Size: 9.78 MB - Last synced at: 23 days ago - Pushed at: over 1 year ago - Stars: 3 - Forks: 0

harismuneer/Round-Robin-Scheduler

🤹 A C++ implementation of the Round Robin Scheduler algorithm for process scheduling.

Language: C++ - Size: 143 KB - Last synced at: 2 months ago - Pushed at: 10 months ago - Stars: 17 - Forks: 10

markCwatson/toyos

Learning operating system and kernel development by building a multithreaded OS called ToyOS

Language: C - Size: 3.72 MB - Last synced at: about 1 month ago - Pushed at: 4 months ago - Stars: 14 - Forks: 1

Klus3kk/queuenotification

A queue-based notification system made with IPC mechanisms.

Language: C - Size: 30.3 KB - Last synced at: about 1 month ago - Pushed at: 10 months ago - Stars: 1 - Forks: 0

EnderIce2/Fennix

Opeating System from scratch made in C and C++

Language: C++ - Size: 77.2 MB - Last synced at: 4 months ago - Pushed at: 5 months ago - Stars: 3 - Forks: 1

MartinUbl/KIV-RTOS

Sources and documents for KIV/OS (Operating Systems) course - development of Raspberry Pi Zero W (BCM2835) operating system.

Language: C++ - Size: 3.98 MB - Last synced at: 5 months ago - Pushed at: 5 months ago - Stars: 5 - Forks: 7

f3nr1rs3c/OpenSource_OperatingSystems

Açık Kaynak İşletim Sistemleri ders notları

Size: 47.9 KB - Last synced at: 5 months ago - Pushed at: 5 months ago - Stars: 1 - Forks: 0

samiyaalizaidi/Multithreaded-Client-Server-in-C

A multi-threaded client-server application for concurrent file transfer with SHA256 data integrity verification.

Language: C - Size: 21.5 KB - Last synced at: 3 months ago - Pushed at: 11 months ago - Stars: 2 - Forks: 0

kivimango/visage

Language: Rust - Size: 14.6 KB - Last synced at: 5 months ago - Pushed at: over 5 years ago - Stars: 1 - Forks: 0

shannatobf/LearnUbuntu

Documentation based repo for learning Linux OS Ubuntu.

Size: 12.7 KB - Last synced at: 6 months ago - Pushed at: 6 months ago - Stars: 1 - Forks: 0

reekid420/os

x86 os (hopefully x86_64 in the future)

Language: Rust - Size: 98.6 KB - Last synced at: 6 months ago - Pushed at: 6 months ago - Stars: 0 - Forks: 0

nonbinarybyte/CelestiaOS

CelestiaOS

Size: 54.7 KB - Last synced at: 6 months ago - Pushed at: 6 months ago - Stars: 0 - Forks: 0

alisharify7/operating-system-course

a full course for operating-system lectures + My own additional content. base on Abraham-Silberschatz-Operating-System-Concepts-10th-2018

Language: HTML - Size: 587 MB - Last synced at: 6 months ago - Pushed at: 11 months ago - Stars: 41 - Forks: 1

TochusC/Ource

[操作系统满分课设(100分)] 一个实现了最最基本的中断处理、时钟管理、原语操作和资源管理支撑功能的系统内核! (十分简陋) [Operating System Full Score Course Design (100 points)] A system kernel that implemented the most basic interrupt handling, clock management, primitive operations, and resource management! (Very crude)

Language: C - Size: 45.8 MB - Last synced at: 7 months ago - Pushed at: 7 months ago - Stars: 1 - Forks: 0

mthipparthi/operating-systems-three-easy-pieces

operating systems three easy pieces by Rezmi

Language: C++ - Size: 10.2 MB - Last synced at: 8 months ago - Pushed at: almost 3 years ago - Stars: 451 - Forks: 99

gjlee0802/operating-system

(기본)OS 복습

Size: 148 KB - Last synced at: 8 months ago - Pushed at: 8 months ago - Stars: 0 - Forks: 0

FrankRay78/PatienceOS 📦

A baremetal C# kernel.

Language: C# - Size: 98.6 KB - Last synced at: 7 months ago - Pushed at: over 1 year ago - Stars: 26 - Forks: 6

mzsqr/rx-os

🦀️ Rust Extended xv6-riscv

Language: Rust - Size: 935 KB - Last synced at: 7 months ago - Pushed at: 7 months ago - Stars: 3 - Forks: 0

twinik/TP-SistemasOperativos

Trabajo práctico de Sistemas Operativos, 2024, UTN

Language: C - Size: 621 KB - Last synced at: 23 days ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

https-dre/square-kernel

Um kernel x86 leve desenvolvido por hobby com C e Assembly.

Language: C - Size: 308 KB - Last synced at: 5 months ago - Pushed at: 5 months ago - Stars: 8 - Forks: 0

0mega28/OS

Operating System from scratch.

Language: C - Size: 165 KB - Last synced at: 6 months ago - Pushed at: over 4 years ago - Stars: 6 - Forks: 5

Doctor-Coomer/core-util

μtil (pronounced roughly 'mew-til', or could be written as 'mutil') is intended to be a micro-sized-utility for Linux and possibly other Unix-like kernels.

Language: C - Size: 340 KB - Last synced at: 4 months ago - Pushed at: 10 months ago - Stars: 0 - Forks: 0

lorenzomaiuri-dev/memory-management-examples

A Python-based simulator showcasing memory management concepts such as allocation strategies, segmentation, pagination, swapping, and TLB. Interactive examples implemented in Jupyter notebooks

Size: 545 KB - Last synced at: 10 months ago - Pushed at: 10 months ago - Stars: 0 - Forks: 0

ull-esit-sistemas-operativos/ssoo-apuntes

Clases de Sistemas Operativos. Apuntes de la asignatura.

Language: Ruby - Size: 30.9 MB - Last synced at: 10 months ago - Pushed at: 10 months ago - Stars: 6 - Forks: 2

lrmulkayhee/javascript-os

JavaScript OS is a comprehensive operating system simulation written in JavaScript. It provides a wide range of functionalities including process management, memory management, file system operations, and more.

Language: JavaScript - Size: 87.9 KB - Last synced at: 6 months ago - Pushed at: 10 months ago - Stars: 0 - Forks: 0

videlanicolas/os_learning

Learning how to make an OS from scratch.

Language: Assembly - Size: 50.8 KB - Last synced at: 8 months ago - Pushed at: 10 months ago - Stars: 1 - Forks: 0

camerondurham/cs350-docker

Docker container and run scripts for MIT's xv6 kernel. Useful for USC CSCI 350.

Language: Shell - Size: 346 KB - Last synced at: about 1 month ago - Pushed at: almost 2 years ago - Stars: 32 - Forks: 7

vs4vijay/VizOS

VizOS

Language: Rust - Size: 8.79 KB - Last synced at: 9 months ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

rodyherrera/ChittyOS

ChittyOS is a minimal and basic operating system, it was created just to test my skills, no contributions expected, it's just a hobby :), most of the source code is commented, you can learn from him.

Language: C - Size: 60.5 KB - Last synced at: 6 months ago - Pushed at: about 1 year ago - Stars: 1 - Forks: 0

Zannatul-Naim/Operating-Systems-Lab

CSE-3242 Operating Systems Lab

Language: C - Size: 40 KB - Last synced at: 8 months ago - Pushed at: 11 months ago - Stars: 0 - Forks: 1

tcfw/beehiveOS

Beehive OS

Language: Assembly - Size: 5.85 MB - Last synced at: 7 months ago - Pushed at: about 1 year ago - Stars: 2 - Forks: 0

thimc/9intro

code snippets for the book "Introduction to Operating Systems Abstractions using Plan 9" by Francisco J Ballesteros with my notes and solutions (WIP)

Language: C - Size: 80.1 KB - Last synced at: 9 months ago - Pushed at: almost 2 years ago - Stars: 2 - Forks: 0

AbdullahRFA/Operating_System

All codes related with Operating System are available here like (Dead look, Banker's Algorithm,System call (),Process Synchronization, Disk scheduling and others necessary algorithm)

Language: C++ - Size: 182 KB - Last synced at: 6 months ago - Pushed at: about 1 year ago - Stars: 0 - Forks: 0

KidneyOS/KidneyOS

Rust-based toy operating system

Language: Rust - Size: 2.85 MB - Last synced at: about 1 year ago - Pushed at: about 1 year ago - Stars: 13 - Forks: 0

cworld1/osp-learning

Some notes and code about CWorld learning Operating System Principle

Language: TypeScript - Size: 6.2 MB - Last synced at: 8 months ago - Pushed at: about 1 year ago - Stars: 1 - Forks: 0

notch1p/os2024

spaghetti code at its finest.

Language: C - Size: 1.6 MB - Last synced at: about 1 year ago - Pushed at: about 1 year ago - Stars: 0 - Forks: 0

WaqasZafar9/Operating-system-prototype

A prototype Project of Simple operating system functions

Language: Java - Size: 30.3 KB - Last synced at: about 2 months ago - Pushed at: almost 2 years ago - Stars: 4 - Forks: 0

MaxDesiatov/Hleeb

Swift running on bare metal Raspberry Pi

Language: C - Size: 43 KB - Last synced at: 6 months ago - Pushed at: over 3 years ago - Stars: 20 - Forks: 1

TravorLZH/LearnOS

A repo that contains all the code written in my study of OS development.

Language: Assembly - Size: 735 KB - Last synced at: 8 months ago - Pushed at: over 7 years ago - Stars: 3 - Forks: 0

nthnn/Zync-OS

Mock-up bootloader and kernel-only operating system with a very basic boring shell written in pure Assembly.

Language: Assembly - Size: 80.1 KB - Last synced at: 9 months ago - Pushed at: almost 2 years ago - Stars: 1 - Forks: 0

Shreehari-Acharya/OSTEP-Notes

Homework solutions for the book - Operating Systems: Three Easy Pieces

Size: 174 KB - Last synced at: over 1 year ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

ndbaker1/koala

ʕ •ᴥ•ʔ A Toy Programming Language that compiles to its own ISA and runs on a Virtual Machine

Language: Rust - Size: 1.1 MB - Last synced at: 8 months ago - Pushed at: about 3 years ago - Stars: 4 - Forks: 0

MirMohammadd/alinix

alinix is a sophisticated operating system kernel designed to embody the spirit of innovation and reliability in the tech industry. With a focus on efficiency and performance, this kernel represents a fusion of cutting-edge technology and meticulous design principles.

Language: C - Size: 13.8 MB - Last synced at: over 1 year ago - Pushed at: over 1 year ago - Stars: 3 - Forks: 2

ananyagupta254/Multi-threading

Language: Python - Size: 1000 Bytes - Last synced at: over 1 year ago - Pushed at: over 6 years ago - Stars: 0 - Forks: 0

nickknz/HariboteOS

《Make OS Within 30 Days》implemented on Mac using NASM, GCC, QEMU

Language: C - Size: 2.88 MB - Last synced at: about 1 year ago - Pushed at: over 1 year ago - Stars: 6 - Forks: 2

My-College-Work/Operating-System

Here you will get implementation of different OS problems.

Language: C - Size: 16.6 KB - Last synced at: over 1 year ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

Levichu51/SistemasOperativos-Practicas-23-24

Prácticas de la asignatura de Sistemas Operativos UDC 23/24

Language: C - Size: 28.3 KB - Last synced at: 6 months ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 1

Mobiwn/Operating-Systems-Lab

📚 Curated materials and experiments for the Operating Systems Laboratory course, designed for undergraduate Computer Engineering students at Urmia University.

Size: 12.9 MB - Last synced at: 9 months ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

WinsDominoes/kernel

A basic operating system kernel, by me. This will be updated everyday if I have time. This kernel is based on https://github.com/iknowbrain/NIDOS.

Language: C - Size: 85.9 KB - Last synced at: 5 months ago - Pushed at: over 4 years ago - Stars: 2 - Forks: 0

ktlansing/ktlansing

Katie Lansing's Professional Portfolio

Language: C - Size: 177 KB - Last synced at: over 1 year ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

MatiasCarabella/operative-systems-utn-frba

Language: C - Size: 44.9 KB - Last synced at: 6 months ago - Pushed at: over 4 years ago - Stars: 0 - Forks: 0

chirag-droid/NexOS

NexOS is a hobby oprating system written in Rust.

Language: Rust - Size: 3.67 MB - Last synced at: 6 months ago - Pushed at: almost 2 years ago - Stars: 6 - Forks: 0

Zizo001/Poisson-Page-Fault-Detection

Program that aims to illustrate the difference between page fault detection algorithms depending on how their respective queues are managed by the OS

Language: C++ - Size: 28.3 KB - Last synced at: 22 days ago - Pushed at: over 4 years ago - Stars: 1 - Forks: 0

vinsdragonis/NoobOS

A simple barebones OS kernel template for developers to get started with OS dev

Language: C - Size: 55.7 KB - Last synced at: over 1 year ago - Pushed at: over 1 year ago - Stars: 15 - Forks: 3

alexdboxall/ATOS

ATOS is an operating system inspired by OS/161. It is designed to be lightweight and easy to understand. Currently implemented for x86, but should be easy to port to other platforms.

Language: C - Size: 22.3 MB - Last synced at: over 1 year ago - Pushed at: over 2 years ago - Stars: 9 - Forks: 0

Stellaris-code/LudOS

A toy monolithic kernel written in C++

Language: C++ - Size: 265 MB - Last synced at: over 1 year ago - Pushed at: over 6 years ago - Stars: 48 - Forks: 5

josehu07/hux-kernel

The Hux x86 32-bit Toy Operating System Kernel (with full wiki pages)

Language: C - Size: 8.43 MB - Last synced at: over 1 year ago - Pushed at: almost 4 years ago - Stars: 58 - Forks: 1

raissaputi/os232

os232

Language: Shell - Size: 131 KB - Last synced at: over 1 year ago - Pushed at: almost 2 years ago - Stars: 0 - Forks: 0

MM120-i/OS-Algorithms

Simulations of OS Algorithms

Language: C - Size: 49.8 KB - Last synced at: over 1 year ago - Pushed at: over 1 year ago - Stars: 0 - Forks: 0

RiordanIX/Coolix

C++ Simulated Operating System

Language: C++ - Size: 7.39 MB - Last synced at: over 1 year ago - Pushed at: almost 8 years ago - Stars: 3 - Forks: 1

amuuu/os-notes

Notes about operating systems collected from all over the internet and my brain.

Size: 2 MB - Last synced at: over 1 year ago - Pushed at: almost 6 years ago - Stars: 5 - Forks: 3

amuuu/amu-xv6

Adding system calls, scheduling algorithms, and timers to xv6

Language: C - Size: 131 KB - Last synced at: over 1 year ago - Pushed at: almost 6 years ago - Stars: 0 - Forks: 0

Mariona-FT/Operating-Systems-SIOP

SISTEMES OPERATIUS Curs 2021-22 EPSEVG

Language: C - Size: 23 MB - Last synced at: 7 months ago - Pushed at: over 1 year ago - Stars: 2 - Forks: 0

iansmith/parigot

Develop as a monolith, deploy as microservices.

Language: Go - Size: 195 MB - Last synced at: over 1 year ago - Pushed at: about 2 years ago - Stars: 12 - Forks: 1

Mjz86/mjz_esp32_os

a open source operating system for running wrench byte code in a esp32 / esp32s3

Language: C++ - Size: 4.43 MB - Last synced at: 7 months ago - Pushed at: about 2 years ago - Stars: 1 - Forks: 0

Rob2309/SimpleOS2

SimpleOS2 is a very simple x86_64 OS I am creating for learning purposes.

Language: C - Size: 3.51 MB - Last synced at: about 1 month ago - Pushed at: over 4 years ago - Stars: 7 - Forks: 2

matheuspb/nanvix Fork of nanvix/nanvix

An Operating System for Manycore Platforms

Language: C - Size: 8.08 MB - Last synced at: almost 2 years ago - Pushed at: over 8 years ago - Stars: 0 - Forks: 0

codebyrpp/pintos-projects

My solutions for the Labs for undergraduate OS class (600.318) at Johns Hopkins. Pintos is a teaching operating system for x86, challenging but not overwhelming, small but realistic enough to understand OS in depth

Language: C - Size: 683 KB - Last synced at: 6 months ago - Pushed at: almost 2 years ago - Stars: 0 - Forks: 0

haadiyeah/Construction-Site-Simulator

Simulation of a construction site using Operating Systems concepts, such as memory management, resource management, synchronization and more.

Language: C++ - Size: 196 KB - Last synced at: 8 months ago - Pushed at: almost 2 years ago - Stars: 0 - Forks: 0

varshneydevansh/devOS

This is my tutorial on OS

Language: Assembly - Size: 416 KB - Last synced at: 7 months ago - Pushed at: almost 8 years ago - Stars: 5 - Forks: 0

FutureMillennium/OS-dev-Windows-start

Tutorial: getting started with OS development in assembly and C/C++ (GCC) on Windows

Language: Assembly - Size: 6.84 KB - Last synced at: over 1 year ago - Pushed at: over 9 years ago - Stars: 11 - Forks: 2

akhilsurnedi5479/Labs

Language: Java - Size: 7.16 MB - Last synced at: almost 2 years ago - Pushed at: over 7 years ago - Stars: 0 - Forks: 0

RedFox0x20/RedFox32_Old 📦

A self learning exercise in low level system programming (OS and kernel programming) for the x86 architecture.

Language: C - Size: 1.9 MB - Last synced at: almost 2 years ago - Pushed at: over 4 years ago - Stars: 8 - Forks: 1

yusufaktog/students-in-library

An example usage of threads in java

Language: Java - Size: 3.91 KB - Last synced at: almost 2 years ago - Pushed at: about 4 years ago - Stars: 1 - Forks: 0

algorhtym/os-works

A compilation of C code implementations for core operating systems (OS) concepts utilizing Linux system programming through pthreads, stdio manipulation, pipes, file operations, interprocess communication etc.

Language: C - Size: 4.88 KB - Last synced at: almost 2 years ago - Pushed at: over 2 years ago - Stars: 0 - Forks: 0

KonnerV/Zaeros

A simple hobbyist operating system.

Language: C - Size: 105 KB - Last synced at: almost 2 years ago - Pushed at: almost 2 years ago - Stars: 3 - Forks: 0