#include <bits/stdc++.h>
using namespace std;
int v[10] = {0, 0, 2, 3, 223, 5, 35, 7, 7222, 7332};
int a[100];
char s[20];
int i, j, n, m, p, x;
int main() {
  scanf("%d", &n);
  scanf("%s", s);
  p = 0;
  for (i = 0; i < n; i++) {
    x = v[s[i] - '0'];
    while (x) {
      a[++p] = x % 10;
      x /= 10;
    }
  }
  sort(a + 1, a + 1 + p);
  for (i = p; i >= 1; i--) printf("%d", a[i]);
  printf("\n");
  return 0;
}

### Prompt

Create a solution in cpp for the following problem:

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>

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int v[10] = {0, 0, 2, 3, 223, 5, 35, 7, 7222, 7332};
int a[100];
char s[20];
int i, j, n, m, p, x;
int main() {
  scanf("%d", &n);
  scanf("%s", s);
  p = 0;
  for (i = 0; i < n; i++) {
    x = v[s[i] - '0'];
    while (x) {
      a[++p] = x % 10;
      x /= 10;
    }
  }
  sort(a + 1, a + 1 + p);
  for (i = p; i >= 1; i--) printf("%d", a[i]);
  printf("\n");
  return 0;
}

```