#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream fin("euclid2.in");
    ofstream fout("euclid2.out");
    int x,y,aux;
    fin>>x>>y;
    if(y<x)
    {
        aux=x;
        x=y;
        y=aux;
    }
    if(x==0)
        fout<<y;
    else
        {
            while(x!=y)
            {
                if(y>x)
                    y=y-x;
                else x=x-y;
            }
        fout<<y;
        }
    return 0;
}