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

const double pi  = 2 * acos(0.0);
const double eps = 1e-8;

#define REP(i,a,b) for(int i=(a); i<(b);++i)
#define rep(i,n) REP(i,0,n)
#define INF (1<<29)
#define INFLL (1LL<<61)

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

int dx[8] = {0, 1, 0, -1, 1, -1, 1, -1};
int dy[8] = {1, 0, -1, 0, 1, -1, -1, 1};

int main(void) {
  ios_base::sync_with_stdio(false); cin.tie(0);
  ll N, T;
  cin >> N;

  ll NC = 0;
  T = N;
  while (T != 0) {
    NC += T;
    T /= 2;
  }

  ll ans = -1;
  for (int i = 0; i < 61; i++) {
    ll S = 0;
    T = N;
    for (int j = 0; T != 0; j++, T /= 2) {
      if (j == i) {
        S += T * 2;
        break;
      } else {
        S += T;
      }
    }
    ans = max(S, ans);
  }

  ans = ans - NC;

  cout << ans << endl;
  return 0; 
}