#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;

int main(){
	ll n;
	cin >> n;
	ll m=n, cnt=0, score=0;
	while(m>0){
		score+=m;
		cnt++;
		m/=2;
	}
	ll ans=0;
	for(int i=0; i<cnt; i++){
		ll score_t=0, m=n;
		for(int j=0; j<i-1; j++){
			score_t+=m;
			m/=2;
		}
		score_t+=2*m;
		ans=max(ans, score_t-score);
	}
	cout << ans << endl;
	return 0;
}