#include <bits/stdc++.h>
using namespace std;
#ifdef tabr
#include "library/debug.cpp"
#else
#define debug(...)
#endif

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    long long n;
    cin >> n;
    if (n == 1 || n == 3) {
        cout << 2 << '\n';
        return 0;
    } else if (n == 2) {
        cout << 3 << '\n';
        return 0;
    }
    for (long long p = 2; p * p <= n; p++) {
        long long m = n;
        long long q = m % p;
        bool ok = true;
        while (m) {
            if (m % p != q) {
                ok = false;
                break;
            }
            m /= p;
        }
        if (ok) {
            cout << p << '\n';
            return 0;
        }
    }
    vector<long long> d;
    for (long long p = 1; p * p <= n; p++) {
        if (n % p == 0) {
            d.emplace_back(n / p - 1);
        }
    }
    reverse(d.begin(), d.end());
    for (long long p : d) {
        if (n / (p + 1) <= p - 1) {
            cout << p << '\n';
            break;
        }
    }
    return 0;
}