#include <bits/stdc++.h>
    using namespace std;
    #include <math.h>
    #include <iomanip>
    #include <cstdint>
    #include <string>
    #include <sstream>
    template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
    template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
    #define rep(i,n) for (int i = 0; i < (n); ++i)
    typedef long long ll;
    using P=pair<ll,ll>;
    const int INF=1001001001;
    const int mod=1e9+7;
    
    int main() {
      ll N;
      cin>>N;
      vector<ll>res;
      for(ll j=N;j>0;j=(j-1)&N){res.push_back(j);}
      int n=res.size();
      cout<<res[n/2]<<endl;
      return 0;
    }