#include "bits/stdc++.h"

using lint = int64_t;

using namespace std;

map<lint,lint> memo;

int countDiv(lint x) {
    set<lint> st;
    for(lint i = 1; i <= sqrt(x) + 1; i++) {
        if(x % i == 0) {
            st.insert(i);
            st.insert(x/i);
        }
    }
    return st.size();
}

lint f(lint x) {
    int cnt = countDiv(x);
    return lint(round(pow(x, cnt)));
}

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  lint n;
  cin >> n;
  for(int i = 2; i <= 70; i++) {
    lint raiz = round(pow(n, 1.0/i));
    // cout << raiz << endl;
    if(f(raiz) == n) {
        cout << raiz << endl;
        return 0;
    }
  }
  cout << -1 << endl;
  return 0;
}