#include <iostream>
#include <fstream>
using namespace std;

ifstream f("euclid2.in");
ofstream g("euclid2.out");

int cmmdc(long long a, long long b)
{
    if(!b) return a;
    else return cmmdc(b,a%b);
}

int main()
{
    long long a,b;
    f>>a>>b;
    g<<cmmdc(a,b);
    return 0;
}