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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll n, m;
    cin >> n >> m;
    if(n % 2 == 0){
        cout << n * m << '\n';
        return 0;
    }
    ll ans = 0, d = 0, mx = 0;
    for(int i = 30; i >= 0; i--){
        if(m >> i & 1){
            mx = max(mx, ans + (n - 1) * ((1ll << i) - 1));
            ans += (n - 1) * (1ll << i);
            d = min(n, d + 1);
        }else{
            ans += ((d / 2) * 2) * (1ll << i);
        }
    }
    ans = max(ans, mx);
    cout << ans << '\n';
}