#include <bits/stdc++.h>
#define ll long long

using namespace std;

int main() {
	ll p, n;
	unordered_set<ll> marked;
	marked.insert(0);

	cin >> p >> n;

	ll sum = 0;
	for(int i = 1; i <= min(p * 2, n); i++) {
		sum = (sum + i) % p;
		marked.insert(sum);
	}

	cout << marked.size() << endl;

	return 0;
}