#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using pii = pair<int, int>;
template <class T>
using V = vector<T>;
template <class T>
using VV = V<V<T>>;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define rep(i, n) rep2(i, 0, n)
#define rep2(i, m, n) for (int i = m; i < (n); i++)
#define per(i, b) per2(i, 0, b)
#define per2(i, a, b) for (int i = int(b) - 1; i >= int(a); i--)
#define ALL(c) (c).begin(), (c).end()
#define SZ(x) ((int)(x).size())

constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }

template <class T, class U>
void chmin(T &t, const U &u) {
    if (t > u) t = u;
}
template <class T, class U>
void chmax(T &t, const U &u) {
    if (t < u) t = u;
}

template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    os << "(" << p.first << "," << p.second << ")";
    return os;
}

template <class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "{";
    rep(i, v.size()) {
        if (i) os << ",";
        os << v[i];
    }
    os << "}";
    return os;
}

#ifdef LOCAL
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << H;
    debug_out(T...);
}
#define debug(...) \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif

using R = __int128_t;

const ll INF = TEN(18) + 10;

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

    auto calc = [&](ll x, int t) {
        R s = 0;
        R cur = x;
        rep(j, t) {
            s += cur;
            cur /= 2;
        }
        return s;
    };

    rep(i, 60) {
        ll lo = 0, hi = INF;
        while (hi - lo > 1) {
            ll m = (lo + hi) / 2;
            R s = calc(m, i + 1);
            if (s <= D) {
                lo = m;
            } else {
                hi = m;
            }
        }
        if (calc(lo, i + 1) == D) {
            ans = lo;
        }
    }
    cout << ans << endl;
    return 0;
}