#include <stdio.h>

int GCD(int a, int b) {
    if (b == 0)
        return a;
    else
        return GCD(b, a % b);
}
int main () {
    int a, b;
    scanf("%d", &a);
    scanf("%d", &b);
    if (a<= 0|| b<= 0) {
        printf("Invalid input/n");
    } else {
        printf("%d",gcd(a,b));
    }
    return 0;
    
}