#include <bits/stdc++.h>
using namespace std;
using ll = int_fast64_t;
constexpr int mod = 1e9 + 7;
constexpr int inf = (1 << 30) - 1;
constexpr ll infll = (1LL << 61) - 1;
#define fast() ios::sync_with_stdio(false), cin.tie(nullptr)
#define set_digit(N) cout << fixed << setprecision((N))
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

ll func(ll x)
{
	ll sum = 0;
	while (x > 0)
	{
		sum += x;
		x /= 2;
	}
	return sum;
}

int main()
{
	ll D;
	cin >> D;

	ll ng = 0, ok = D;

	while (ok - ng > 1)
	{
		ll mid = (ok + ng) / 2;
		if (func(mid) >= D)
		{
			ok = mid;
		}
		else
		{
			ng = mid;
		}
	}

	cout << ok << "\n";
}