#include <iostream>
#include <vector>
#include <string>
using namespace std;
typedef long long ll;

ll gcd(ll a, ll b) {
	while (a) {
		b %= a;
		swap(a, b);
	}
	return b;
}

int main()
{
	ll a, b; cin >> a >> b;
	ll c = a + b;

	ll d, e;
	d = gcd(c, a);
	e = gcd(d, b);


	ll ans = gcd(d, e);

	cout << ans << endl;

    return 0;
}