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

using Int = long long;
const char newl = '\n';

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}
template<typename T=Int>
vector<T> read(size_t n){
  vector<T> ts(n);
  for(size_t i=0;i<n;i++) cin>>ts[i];
  return ts;
}

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  Int d;
  cin>>d;

  auto calc=[&](Int x,Int t){
    Int sum=0;
    for(Int i=0;i<t;i++){
      sum+=x;
      x>>=1;
    }
    return sum;
  };

  const Int LOG = 60;
  for(Int t=LOG;t>=0;t--){
    Int L=0,R=d+1;
    while(L+1<R){
      Int M=(L+R)>>1;
      if(calc(M,t)<d) L=M;
      else R=M;
    }
    if(calc(R,t)==d) drop(R);
  }
  return 0;
}