#include <stdio.h>

int A, B;

int gcd(int a, int b)
{
    if (!b) return a;
    return gcd(b, a % b);
}

int main(void)
{
    freopen("euclid2.in", "r", stdin);
    freopen("euclid2.out", "w", stdout);

    scanf("%d %d", &A, &B);
    printf("%d\n", gcd(A, B));

    return 0;
}