/*
*/

#include <stdio.h>

int main() {
    int a, b, R;
    scanf("%d%d", &a, &b);

    while (1) {
        R = a % b;
        if(R == 0) break;
        else {
            a = b;
            b = R;
        }
    }
    printf("%d", b);
    return 0;
}

a = input()
b = input()
R = a % b