//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;





void solve(){
    ll N, M;
    cin >> N >> M;
    if(!(N & 1)){
        cout << M * N << "\n";
        return;
    }
    ll cnt = 0;
    ll ans = 0;
    for(int i = 32; i >= 0; --i){
        if((M >> i) & 1){
            ++cnt;
            ans += (N - 1) << i;
        }else{
            ans += ((cnt / 2) * 2) << i;
        }
        cnt = min(cnt, N);
    }
    cout << ans << "\n";
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << setprecision(10) << fixed;

    int T;
    T = 1;
    //cin >> T;
    for(;T--;) solve();
}