/* A program to perform Euclid's
Algorithm to compute gcd. */
int gcd(int u,int v)
{  
   if (v==0) 
	return u;
   else 
  	return gcd(v,u-u/v*v);
  /* u-u/v*v==u mod v */
}
void main(void)
{ 
   int x; 
   int y;
   x = input(); 
   y = input();
   output(gcd(x,y));
}