#include <cstdio>
#include <cstdlib>
#include <cstddef>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <iostream>
#include <iomanip>
#define L64 long long
#define MOD (998244353LL)

int main(void)
{
  L64 n;
  std::cin >> n;
  L64 mcand = 0;
  L64 sum = 0;
  while(0 < n){
    mcand = std::max(mcand, sum + n * 2);
    sum += n;
    n /= 2LL;
  }
  std::cout << mcand - sum << std::endl;
  return 0;
}