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

using ll = long long;

bool chmin(auto &a, auto b) { return a > b ? a = b, true : false; }
bool chmax(auto &a, auto b) { return a < b ? a = b, true : false; }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll N, M;
    cin >> N >> M;
    if (N % 2 == 0) {
        cout << N * M << endl;
        return 0;
    }
    ll ans = 0;
    for (int i = 29, k = 0; i >= 0; i--) {
        if (M >> i & 1) {
            ans += (N - 1) * (1 << i);
            k++;
        } else {
            ans += 2 * (min<ll>(N, k) / 2) * (1LL << i);
        }
    }
    cout << ans << endl;
}