// editor4
#include <stdio.h>
3include <stdlib.h>
int gcd(int n, int m) {
    while (m != 0) {
        int temp = m;
        m = n % m;
        n = temp;
    }
    return n;
}
int main(){
    int n, m;
    scanf("%d %d", &n, &m);
    if(n < -100 || n > 100 || m < -100 || m > 100){
        printf("Invalid input\n");
}else{
    int abs_n = abs(n);
    int abs_m = abs(m);
    
    if (abs_n == 0 && abs_m == 0) {
        printf("Invalid input\n");
    }else{
        int result = gcd(abs_n, abs_m);
        printf("%d\n", result);
    }
}
return 0;
}