#include <stdio.h>

int gcd(int m, int n){
    if(n == 0){
        return m;
    }else{
        return gcd(n, m % n);
    }
}

int main(void){
    int a, b;

    scanf("%d,%d", &a, &b);

    if(a >= b){
        printf("%d\n", gcd(a, b));
    }else{
        printf("%d\n", gcd(b, a));
    }

    return 0;
}