#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using pii = pair <int, int>;
const ll mod = 998244353;
//~ const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
	for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }

int main() {
	ios :: sync_with_stdio(false);
	
	ll d; cin >> d;
	for(ll i = d / 2; ; i ++) {
		ll s = 0, x = i;
		while(s < d && x) {
			s += x;
			x /= 2;
		}
		if(s == d) {
			cout << i << '\n';
			return 0;
		}
	}
}