#include <iostream>
#include <fstream>
#include <sstream>
using namespace std;
int main()
{
    ifstream in("euclid2.in");
    ofstream out("euclid2.out");
    int a,b;in >> a >> b;
    int auxa =a;
    int auxb = b;
    a = max(auxa,auxb);
    b = min(auxa,auxb);
    //cout << a << " " <<b;
    while(true)
    {
        if(a%b == 0)
        {
            out << b;
            return 0;
        }
        else
        {
            int aux = a%b;
            a = b;
            b = aux;
        }
    }

    return 0;
}