#include <iostream>

int gcd(int a, int b) {
	if (a == b) return a;
	if (a > b)  return gcd(a-b, b);
	return gcd(b, a);
}

int main() {
	int a, b;
	std::cin >> a >> b;
	std::cout << gcd(a, b) << std::endl;
}