#include <iostream>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    ll N;
    cin >> N;
    ll ma = 0, sum = 0;
    while(N > 0) {
        ma = max(ma, sum + N * 2);
        sum += N;
        N >>= 1;
    }
    cout << ma - sum << endl;
}