#include<stdio.h>

int gcd(int a, int b)
{
    if(b == 0)
        return a;
    return gcd(b, a % b);
}

int main()
{
    FILE *f = fopen("euclid2.in", "r");
    FILE *g = fopen("euclid2.out", "w");
    int a, b, c;
    fscanf(f, "%d", &a);
    fscanf(f, "%d", &b);
    c = gcd(a,b);
    fprintf(g, "%d", c);
    fclose(f);
    fclose(g);
}