Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

First, they choose a decimal number a consisting of n digits that contains at least one digit larger than 1. This number may possibly start with leading zeroes. Then they should find maximum positive number x satisfying following two conditions:

1. x doesn't contain neither digit 0 nor digit 1.

2. <image> = <image>.

Help friends find such number.

Input

The first line contains an integer n (1 ≤ n ≤ 15) — the number of digits in a.

The second line contains n digits of a. There is at least one digit in a that is larger than 1. Number a may possibly contain leading zeroes.

Output

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[99];
  int n, i, j, x, p, ans[99], a[4] = {0}, d[4] = {2, 3, 5, 7}, k;
  cin >> n >> s;
  for (i = 0; i < n; i++) {
    x = s[i] - '0';
    for (p = 2; p <= x; p++) {
      j = p;
      for (k = 0; k < 4; k++)
        while (j % d[k] == 0) {
          j /= d[k];
          a[k]++;
        }
    }
  }
  k = 0;
  while (a[3] > 0) {
    ans[k++] = 7;
    a[3]--;
    a[2]--;
    a[1] -= 2;
    a[0] -= 4;
  }
  while (a[2] > 0) {
    ans[k++] = 5;
    a[2]--;
    a[1]--;
    a[0] -= 3;
  }
  while (a[1] > 0) {
    a[1]--;
    a[0]--;
    ans[k++] = 3;
  }
  while (a[0] > 0) {
    a[0]--;
    ans[k++] = 2;
  }
  sort(ans, ans + k);
  for (i = k - 1; i >= 0; i--) printf("%d", ans[i]);
  printf("\n");
  return 0;
}
