#include <algorithm>
#include <array>
#include <cassert>
#include <cmath>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <vector>

void solve() {
  long long D;
  std::cin >> D;
  auto check = [&](long long mid, int k) {
    long long sum = 0;
    while (k--) {
      sum += mid;
      mid /= 2;
    }
    return sum;
  };
  long long res = std::numeric_limits<long long>::max();
  for (int i = 0; i <= log2(D) + 1; i++) {
    // calc f[x] = D
    long long l = 0, r = D;
    while (l < r) {
      long long mid = l + (r - l) / 2;
      if (check(mid, i) >= D)
        r = mid;
      else
        l = mid + 1;
    }
    if (check(l, i) == D) {
      res = std::min(l, res);
    }
  }
  std::cout << res << '\n';
}
int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  solve();
  return 0;
}