#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353; //1000000007;
using ll=long long;
using pp=pair<ll,ll>;
#define sr string 
#define vc vector
#define fi first
#define se second
#define rep(i,n) for(ll i=0;i<(ll)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
int main(){
  ll d;cin>>d;
  ll ans=0;
  for(ll i=59;i>=0;i--){
    if(d==(1ll<<i)-1){
      ans+=1ll<<(i-1);
      break;
    }
    if(d>>i&1){
      ans+=1ll<<(i-1);
      d++;
    }
  }
  cout<<ans;
}