#include <bits/stdc++.h>
using namespace std;
int main() {
  int a;
  cin >> a;
  vector<int> fac;
  for (int i = 1; i <= a; i++) {
    if (a % i == 0) fac.push_back(i);
  }
  int n = fac.size();
  cout << fac[n / 3] << fac[n / 2] << "\n";
  return 0;
}
