#include <bits/stdc++.h>
using namespace std;
void fre() {
  freopen("c://test//input.in", "r", stdin);
  freopen("c://test//output.out", "w", stdout);
}
template <class T1, class T2>
inline void gmax(T1 &a, T2 b) {
  if (b > a) a = b;
}
template <class T1, class T2>
inline void gmin(T1 &a, T2 b) {
  if (b < a) a = b;
}
const int N = 0, M = 0, Z = 1e9 + 7, inf = 0x3f3f3f3f;
template <class T1, class T2>
inline void gadd(T1 &a, T2 b) {
  a = (a + b) % Z;
}
int casenum, casei;
int n;
int main() {
  int x;
  while (~scanf("%d", &x)) {
    for (int i = 2; i * i <= x; ++i) {
      while (x % i == 0) {
        printf("%d", i);
        x /= i;
      }
    }
    if (x > 1) printf("%d", x);
    puts("");
  }
  return 0;
}
