/* 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));
}