C :

#include<stdio.h>
int main()
{
	int x,y,r;
	while(scanf("%d,%d",&x,&y)!=EOF)
	{
		r=x%y;
		while(x%y!=0)
		{
			x=y;
			y=r;
			r=x%y;
		}
		printf("%d\n",y);
	}
}

C++ :

#include<stdio.h>
#include<iostream>
using namespace std;
int main()
{
	int r,a,b; 
    scanf("%d,%d",&a,&b);    
    
    if(a>=b)
    {
		r=a%b;	
	   	if(r==0)
	    {
	        printf("%d\n",b);
	    }
	    while(r!=0)
	    {
	         
	        a=b;
	        b=r;
	        r=a%b;
	        if(r==0)
	        {
	            printf("%d\n",b);
	                     
	        }    
	             
	    }
	}
	else if(a<=b)
    {
		r=b%a;	
	   	if(r==0)
	    {
	        printf("%d\n",a);
	    }
	    while(r!=0)
	    {
	         
	        b=a;
	        a=r;
	        r=b%a;
	        if(r==0)
	        {
	        
	            printf("%d\n",a);
	                     
	        }    
	             
	    }
	}

    return 0;

}

Java :

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(",");
        int a = Integer.parseInt(str[0]);
        int b = Integer.parseInt(str[1]);
        int Max = Math.max(a,b);
        int Min = Math.min(a,b);
        while (Max % Min != 0){
            int temp = Max % Min;
            Max = Min;
            Min = temp;
        }
        System.out.println(Min);
    }
}

Python :

# coding=utf-8
#python2
a,b = map(int,raw_input().split(','))
if b > a:
    c = a
    a = b
    b = c
i = b
while a%i!=0 or b%i!=0:
    i -= 1
print(i)

C# :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    internal class Program
    {
        static void Main()
        {

            string[] strings = Console.ReadLine().Split(',');
            int a = Convert.ToInt32(strings[0]);
            int b = Convert.ToInt32(strings[1]);
            int c = 0;
            int ans = 0;
            if (b > a) {
            c=b; b=a; a=c;
            }
            for (int i = b; i >=1; --i)
            {

                if (a % i == 0 && b % i == 0)
                {
                    ans = i;
                    break;
                }
            }
            Console.WriteLine(ans); 
            Console.ReadKey();
     
        }
    }
}