a024: 最大公因數 FYI: https://yunlinsong.blogspot.com/2016/02/gcd.html

a024.cpp

#include <iostream>
#include <sstream>

using namespace std;

int main()
{
    int a, b;

    while(cin >> a >> b)
    {
        while( a != 0)
        {
            a = a % b;
            b = b - a;
        }

        cout << b << endl;
    }

    return 0;
}