#include <fstream>
using namespace std;
ifstream in("cmmdc.in");
ofstream out("cmmdc.out");

int cmmdc(int a, int b) {
    if(a == 0 || b == 0) {
        return 0;
    }
    if(a == b) {
        return a;
    }
    if(a > b) {
        return cmmdc(a - b, b);
    } else {
        return cmmdc(a, b - a);
    }
}
int main()
{
    int a,b;
    in>>a>>b;
    out<<cmmdc(a,b);
}