#include <iostream>
#include <fstream>

using namespace std;

//#define CONSOLE

int main() {
    long long a, b, r;
    #ifdef CONSOLE
        cin>>a>>b;
    #else
        ifstream fin("euclid2.in");
        ofstream fout("euclid2.out");
        fin>>a>>b;
    #endif
    while (b != 0) {
        r = a%b;
        a = b;
        b = r;
    }
    #ifdef CONSOLE
        cout<<a<<"\n";
    #else
        fout<<a<<"\n";
    #endif
    return 0;
}