#include <iostream>
#define int long long
using namespace std;

int mulmod(int a, int n, int mod) {
	int ret = 0;
	int tmp = a;
	for (int i = 0; (1LL << i) <= n; i++) {
		if ((n >> i) & 1LL) {
			ret += tmp;
			ret %= mod;
		}
		tmp += tmp;
		tmp %= mod;
	}
	return ret;
}

int gcd(int a, int b) {
	if (b == 0) return a;
	return gcd(b, a % b);
}

int a, b;

signed main() {
	cin >> a >> b;
	
	int c = a + b;
	int d = mulmod(a, b, c);

	cout << gcd(c, d) << endl;
	return 0;
}