#include <bits/stdc++.h>
#include <boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
#define ll int128_t
#define rep(i,x,n) for(ll i=x;i<n;i++)
#define rrep(i,x,n) for(ll i=x;i>=n;i--)
using namespace std;
ll calc(ll n){
  ll c=0;
  while(n>1) n/=2,c++;
  return c;
}
ll cal2(ll idx){
  ll ans=1;
  while(idx--)ans*=2;
  return ans;
}
void solve(){
  ll d;
  cin>>d;
  ll init=d,mx=calc(d),ans=0;
  ll res=cal2(80);
  rrep(i,mx-1,0){
    if((d-cal2(i+1)+1) >0) {d-= (cal2(i+1)-1); ans+= cal2(i);}
    else if((d-cal2(i+1)+1) == 0) {d-= (cal2(i+1)-1); ans+=cal2(i); break;}
    else res=min(res,ans+cal2(i));
  }
  res=min(res,init);
  if(d<=0) res=min(res,ans);
  if(d>0){
    ans=0;
    d=init;
    rrep(i,mx,0){
      if((d-cal2(i+1)+1) >0) {d-= (cal2(i+1)-1); ans+= cal2(i);}
      else if((d-cal2(i+1)+1) == 0) {d-= (cal2(i+1)-1); ans+=cal2(i); break;}
      else res=min(res,ans+cal2(i));
    }
    if(d<0) res=min(res,ans);
  }
  cout<<res<<endl;
}
int32_t main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  solve();
}