#include <iostream>
#include <cstdio>

using namespace std;
int cmmdc(int a, int b)
{
    if(!b)
        return a;
    else
        return cmmdc(b, a%b);
}

int main()
{
    freopen("cmmdc.in", "r", stdin);
    freopen("cmmdc.out", "w", stdout);

    long a, b;
    cin>>a>>b;
    cout<<cmmdc(a, b);
}