#include <bits/stdc++.h>
using namespace std;
int main(){
  long long N;
  cin >> N;
  bool ok = false;
  for (long long i = 2; i <= N; i++){
    long long N2 = N;
    vector<int> A;
    while (N2 > 0){
      A.push_back(N2 % i);
      N2 /= i;
    }
    bool same = true;
    int cnt = A.size();
    for (int j = 1; j < cnt; j++){
      if (A[j] != A[0]){
        same = false;
      }
    }
    if (same){
      cout << i << endl;
      ok = true;
      break;
    }
    if (A.size() <= 2){
      break;
    }
  }
  if (!ok){
    for (int i = (int) sqrt(N); i >= 1; i--){
      if (N % i == 0){
        long long b = N / i - 1;
        if (b > i && N / b == N % b){
          cout << b << endl;
          ok = true;
          break;
        }
      }
    }
    if (!ok){
      cout << N + 1 << endl;
    }
  }
}