#include <stdio.h>

int scd(int a, int b) {
    if (b == 0)
        return a;
    return gcd(b, a % b);
}

int main() {
    int a, b;
    scanf("%d", &a);
    scanf("%d", &b);
    
    if (a <= 0 || b <= 0) {
        printf("Invaild input");
        return a;
    }
    
    int result = gcd(a, b);
    printf("%d", result);
    
    return 0;
}