#include <bits/stdc++.h>
#define ll long long
#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;
}
void solve(){
  ll d;
  cin>>d;
  ll init=d,mx=calc(d),ans=0;//(1LL<<(mx-1LL));
  // d-=((1LL<<mx) -1LL);

  // if(d<=0){ cout<<ans<<endl;return; }
  ll res=1LL<<62;
  rrep(i,mx-1,0){
    if(d-(1LL<<(i+1LL))+1LL >0) {d-= ((1LL<<(i+1LL))-1LL); ans+= (1LL<<i);}
    else if(d-(1LL<<(i+1LL))+1LL == 0) {d-= ((1LL<<(i+1LL))-1LL); ans+=( 1LL<<i); break;}
    else res=min(res,ans+(1LL<<i));
  }
  if(d>0) ans=init;
  cout<<min(res,ans)<<endl;
}
int32_t main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  solve();
}