#include <bits/stdc++.h>
using namespace std;
int main() {
  long long N;
  cin >> N;
  long long a = 0, b = 0;
  for (long long i = 1; i <= sqrt(N); i++) {
    if (N % i == 0) {
      a = i;
      b = N / a;
    }
  }
  cout << a << b << endl;
}
