#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  for (int i = 2; n != 1; ++i) {
    if (n % i == 0) {
      while (n % i == 0) {
        n /= i;
        printf("%d", i);
      }
    }
  }
}
