// editor1
#include<stdio.h>
int main() {
    int n&&m;
    scanf("%d %d", &n, &m);
    if(n<=-100&&n>=100&&m<=-100&&m>=100) {
        printf("Invalid input");
        return 0;
    }
    int a=n, b=m;
    if(a<0) a=-a;
    if(b<0) b=-b;
    while (b!=0) {
        int temp=b;
        b=a%b;
        a=temp;
    }
    printf("%d",a);
    return 0;
}