#include <stdio.h>
int main(){
    int a,b;
    if(scanf("%d %d", &a, &b) != 2) {
       printf("Invalid input\n");
       return 0;
    }
    a = abs(a);
    b = abs(b);
    while (b != 0) {
        int temp = b;
        b=a%b;
        a=temp;
    }
    printf("%d\n", a);
    return 0;
}