#include <bits/stdc++.h>
using namespace std;
#define int long long
#define db double
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) a*b / __gcd(a,b)
#define I first
#define II second
#define pb push_back
#define ii pair<int,int>
const int INF = 2 * 1e18;
const int N = 3e5 + 1;
const int MOD = 1e9 + 7;    
int n, k;
void solve() {
    cin >> n >> k;
    if (n == 1 || k == 0) cout << 0; else 
    if (n % 2 == 0) cout << n * k; else {
        int cnt = 0;
        for (int i = 30; i >= 0; i--)
            if ((k >> i) & 1) {
                int x = k;
                x ^= (1 << i);
                int ok = 0;
                for (int j = i - 1; j >= 0; j--) {
                    if ((k >> j) & 1) ok = 1;
                    if (ok) x ^= (1 << j);
                }
                int y = k ^ x;
                // cout << x << ' ' << y << '\n';
                cout << max((n - 1) * k, k * (n - 2) + x + y);
                return ;
            }
        cout << (n - 1) * k;
    }
}
int32_t main()
{
    #define TASKNAME "test"
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (fopen(TASKNAME ".inp","r" ))
    {
        freopen(TASKNAME ".inp","r",stdin);
        freopen(TASKNAME ".out","w",stdout);
    }
    int t = 1; 
    // cin >> t;
    while (t--) solve();
    return 0;
}