#include <stdio.h>
int main()
{
    int a;
    int b;
    
    if (a<0) a=-a;
    if (b<0) b=-b;
    
    while (b!=0)
    {
        int temp=b;
        b=a%b;
        a=temp;
    }
    return a;
}

int main(){
    int a,b;
    
    if (scanf ("%d %d", &a, &b)!=2)
    {
        printf("Invalid input\n");
        return 0;
    }
    
    int result = gcd (a,b);
    printf("%d\n", result);
    return 0;
}