#include <bits/stdc++.h>
int main() {
  int a, i, j = 0;
  int factors[101];
  scanf("%d", &a);
  for (i = 2; i < a; i++) {
    if (a % i == 0) {
      factors[j++] = i;
    }
  }
  printf("%d%d", factors[0], factors[j - 1]);
}
