#include <iostream>

using namespace std;

unsigned nwd(unsigned a, unsigned b)
{
    if(a * b == 0)
        return 0;
    while(a != b)
    {
        if(a > b)
            a -= b;
        else
            b -= a;
    }
    return a;
}

int main()
{
    unsigned a,b;
    cin >> a >> b;

    cout << nwd(a, b) << endl;
    return 0;
}