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

int main() {
  ios::sync_with_stdio(false);

  int64_t N; { cin >> N; }

  if (N < 3) { cout << N + 1 << endl; return 0; }

  int64_t minv = N - 1; {
    for (int i = 2; (int64_t) i * i <= N; ++i) {
      int64_t n = N;
      int h = n % i;
      bool ok = true;
      for (; n; n /= i) ok &= h == n % i;
      if (ok) minv = min(minv, (int64_t) i);
      if (N % i == 0 && N / i < i - 1) minv = min(minv, (int64_t) i - 1);
      if (N % i == 0 && N / i - 1 > i) minv = min(minv, (int64_t) N / i - 1);
    }
  }

  cout << minv << endl;
}