#include <bits/stdc++.h>
using namespace std;

int main() {
	int N, M; cin >> N >> M;
	
	if (N%2 == 0) {
		cout << (long long) N * M << endl;
		return 0;
	}
	
	int c = 0;
	long long ans = 0;
	for (int b = 29; b >= 0; b--) {
		if (M>>b&1) {
			ans += (N-1) * (1LL << b);
			if (c < N) {
				c++;
			}
		}
		else {
			int use = c / 2 * 2;
			ans += use * (1LL << b);
		}
	}
	
	cout << ans << endl;
}