#include <bits/stdc++.h>
using namespace std;
int cnt[15];
char s[25];
void add(int x) {
  if (x == 0 || x == 1) return;
  if (x == 2 || x == 3 || x == 5 || x == 7) {
    cnt[x]++;
  } else if (x == 4) {
    cnt[2] += 2, cnt[3]++;
  } else if (x == 6) {
    cnt[5]++, cnt[3]++;
  } else if (x == 8) {
    cnt[7]++, cnt[2] += 3;
  } else {
    cnt[7]++, cnt[2]++, cnt[3] += 2;
  }
}
int main() {
  int n;
  scanf("%d%s", &n, s);
  for (int i = 0; i < n; i++) {
    add(s[i] - '0');
  }
  for (int i = 9; ~i; i--) {
    while (cnt[i]--) putchar(i + '0');
  }
  puts("");
  return 0;
}

### Prompt

Please create a solution in cpp to 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 cnt[15];
char s[25];
void add(int x) {
  if (x == 0 || x == 1) return;
  if (x == 2 || x == 3 || x == 5 || x == 7) {
    cnt[x]++;
  } else if (x == 4) {
    cnt[2] += 2, cnt[3]++;
  } else if (x == 6) {
    cnt[5]++, cnt[3]++;
  } else if (x == 8) {
    cnt[7]++, cnt[2] += 3;
  } else {
    cnt[7]++, cnt[2]++, cnt[3] += 2;
  }
}
int main() {
  int n;
  scanf("%d%s", &n, s);
  for (int i = 0; i < n; i++) {
    add(s[i] - '0');
  }
  for (int i = 9; ~i; i--) {
    while (cnt[i]--) putchar(i + '0');
  }
  puts("");
  return 0;
}

```