#include <bits/stdc++.h>
using namespace std;
const int MAX = 1e4 + 4;
const int inf = INT_MAX;
const int MOD = 1e7 + 9;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  vector<bool> prime;
  prime.resize(MAX, true);
  prime[0] = prime[1] = false;
  for (int i = 2; i <= MAX; ++i) {
    if (prime[i] && (long long)i * i <= MAX) {
      for (int j = i * i; j <= MAX; j += i) {
        prime[j] = false;
      }
    }
  }
  vector<int> primes;
  for (int i = 2; i <= MAX; ++i) {
    if (prime[i]) primes.push_back(i);
  }
  int sz = primes.size();
  bool ok = 0;
  for (long long int i = 0; i < sz; ++i) {
    if (ok) break;
    for (long long int j = 0; j < sz; ++j) {
      if (primes[i] * primes[j] == n) {
        cout << primes[i] << primes[j] << endl;
        ok = 1;
        break;
      }
    }
  }
  return 0;
}
