#include <iostream>
using namespace std;

int GCD(int a, int b);

int main() {
	int a, b;
	cin >> a >> b;

	cout << GCD(a, b);
	return 0;
}
int GCD(int a, int b) {
	if (b == 0)
		return a;
	else
		return GCD(b, a%b);
}