// #pragma GCC optimize ("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target ("avx,avx2,fma")
#include <bits/stdc++.h>

using std::cin, std::cout, std::cerr;
using ll = long long;

int main() {
    std::ios::sync_with_stdio(false);
    int n, m; cin >> n >> m;
    ll ans = n / 2 * 2 * ll(m);
    if(n % 2 == 1 && __builtin_popcount(m) >= 2) {
        auto log2 = [](int x) {
            return 31 - __builtin_clz(x);
        };
        m -= 1 << log2(m);
        int i = log2(m);
        m -= 1 << i;
        ans += ((1 << i) - 1 - m) * 2;
    }
    cout << ans << '\n';
}