#include <stdio.h>
#include <math.h>
int main()
{
    int m,n,i;
    int sum=0;
    scanf("%d %d",&m,&n);
while (n!=m)
{
    if (m>n)
         m=m-n;
    else 
       n=n-m;
}
    printf("%d",m);
    return 0;
}