#line 1 "main.cpp"
#include <iostream>

using namespace std;

using lint = long long;
constexpr lint X = 1000000;

void solve() {
    lint n;
    cin >> n;

    for (lint p = 2; p <= X; ++p) {
        lint prev = -1;
        bool ok = true;

        lint m = n;
        while (m > 0) {
            lint r = m % p;
            m /= p;

            if (prev != -1 && r != prev) ok = false;
            prev = r;
        }

        if (ok) {
            cout << p << "\n";
            return;
        }
    }

    lint ans = n;
    for (lint x = 1; x <= X; ++x) {
        if (n % x != 0) continue;
        auto p = n / x - 1;
        if (x < p) ans = min(ans, p);
    }

    cout << ans << "\n";
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    solve();

    return 0;
}