#include <bits/stdc++.h>
using namespace std;
int cnt[10];
void add(int k) {
  if (k == 0 || k == 1) {
    cnt[1]++;
    return;
  }
  for (int i = 1; i <= k; i++) {
    if (i == 1 || i == 2 || i == 3 || i == 5 || i == 7) {
      cnt[i]++;
    } else if (i == 4) {
      cnt[2] += 2;
    } else if (i == 6) {
      cnt[2]++;
      cnt[3]++;
    } else if (i == 8) {
      cnt[2] += 3;
    } else if (i == 9) {
      cnt[3] += 2;
    }
  }
}
int n;
int mult(int k, int curr) {
  if (curr == 1) return 0;
  int result = 0;
  for (int i = 2; i <= k; i++) {
    int x = i;
    while (x % curr == 0) {
      result++;
      x /= curr;
    }
  }
  return result;
}
int main() {
  cin >> n;
  string s;
  cin >> s;
  for (int i = 0; i < n; i++) {
    add((int)(s[i] - '0'));
  }
  for (int i = 9; i >= 2; i--) {
    for (int j = 1; j <= cnt[i]; j++) {
      cout << i;
    }
    int x = cnt[i];
    for (int j = i; j >= 1; j--)
      if (x > 0 && cnt[j] > 0) {
        cnt[j] -= x * mult(i, j);
      }
  }
  cout << endl;
  return 0;
}

### Prompt

Generate a cpp solution 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[10];
void add(int k) {
  if (k == 0 || k == 1) {
    cnt[1]++;
    return;
  }
  for (int i = 1; i <= k; i++) {
    if (i == 1 || i == 2 || i == 3 || i == 5 || i == 7) {
      cnt[i]++;
    } else if (i == 4) {
      cnt[2] += 2;
    } else if (i == 6) {
      cnt[2]++;
      cnt[3]++;
    } else if (i == 8) {
      cnt[2] += 3;
    } else if (i == 9) {
      cnt[3] += 2;
    }
  }
}
int n;
int mult(int k, int curr) {
  if (curr == 1) return 0;
  int result = 0;
  for (int i = 2; i <= k; i++) {
    int x = i;
    while (x % curr == 0) {
      result++;
      x /= curr;
    }
  }
  return result;
}
int main() {
  cin >> n;
  string s;
  cin >> s;
  for (int i = 0; i < n; i++) {
    add((int)(s[i] - '0'));
  }
  for (int i = 9; i >= 2; i--) {
    for (int j = 1; j <= cnt[i]; j++) {
      cout << i;
    }
    int x = cnt[i];
    for (int j = i; j >= 1; j--)
      if (x > 0 && cnt[j] > 0) {
        cnt[j] -= x * mult(i, j);
      }
  }
  cout << endl;
  return 0;
}

```