/* 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));
}