#include <bits/stdc++.h>
using namespace std;
char ch[20];
int ans[10005];
bool cmp(int x, int y) { return x > y; }
int main() {
  int n, i, num = 0, x;
  cin >> n;
  for (i = 0; i <= n; i++) ch[i] = getchar();
  for (i = 1; i <= n; i++) {
    x = ch[i] - 48;
    if (x == 1 || x == 0) continue;
    if (x == 2)
      ans[++num] = 2;
    else if (x == 3)
      ans[++num] = 3;
    else if (x == 4) {
      ans[++num] = 2;
      ans[++num] = 2;
      ans[++num] = 3;
    } else if (x == 5)
      ans[++num] = 5;
    else if (x == 6) {
      ans[++num] = 3;
      ans[++num] = 5;
    } else if (x == 7)
      ans[++num] = 7;
    else if (x == 8) {
      ans[++num] = 2;
      ans[++num] = 2;
      ans[++num] = 2;
      ans[++num] = 7;
    } else if (x == 9) {
      ans[++num] = 7;
      ans[++num] = 2;
      ans[++num] = 3;
      ans[++num] = 3;
    }
  }
  sort(ans + 1, ans + 1 + num, cmp);
  for (i = 1; i <= num; i++) cout << ans[i];
}

### Prompt

Construct a CPP code solution to the problem outlined:

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;
char ch[20];
int ans[10005];
bool cmp(int x, int y) { return x > y; }
int main() {
  int n, i, num = 0, x;
  cin >> n;
  for (i = 0; i <= n; i++) ch[i] = getchar();
  for (i = 1; i <= n; i++) {
    x = ch[i] - 48;
    if (x == 1 || x == 0) continue;
    if (x == 2)
      ans[++num] = 2;
    else if (x == 3)
      ans[++num] = 3;
    else if (x == 4) {
      ans[++num] = 2;
      ans[++num] = 2;
      ans[++num] = 3;
    } else if (x == 5)
      ans[++num] = 5;
    else if (x == 6) {
      ans[++num] = 3;
      ans[++num] = 5;
    } else if (x == 7)
      ans[++num] = 7;
    else if (x == 8) {
      ans[++num] = 2;
      ans[++num] = 2;
      ans[++num] = 2;
      ans[++num] = 7;
    } else if (x == 9) {
      ans[++num] = 7;
      ans[++num] = 2;
      ans[++num] = 3;
      ans[++num] = 3;
    }
  }
  sort(ans + 1, ans + 1 + num, cmp);
  for (i = 1; i <= num; i++) cout << ans[i];
}

```