#include <bits/stdc++.h>
using namespace std;
string n;
int y, k, i, x, len, len1, j, ans[100001];
int main() {
  cin >> len;
  cin >> n;
  for (i = 1; i <= len; ++i) {
    x = n[i - 1] - '0';
    for (j = 1; j <= x; ++j) {
      k = 2;
      y = j;
      while (y > 1) {
        if (y % k == 0)
          ans[++len1] = k, y /= k;
        else
          ++k;
      }
    }
  }
  bool used[1001];
  int pr[1001];
  int sz = 0;
  int kol[10001];
  memset(kol, 0, sizeof kol);
  sort(ans + 1, ans + len1 + 1);
  for (i = 1; i <= len1; ++i) {
    if (!used[ans[i]]) used[ans[i]] = true, pr[++sz] = ans[i];
    kol[ans[i]]++;
  }
  for (i = sz; i >= 1; --i)
    for (int l = 1; l <= kol[pr[i]]; ++l)
      if (kol[pr[i]] > 0)
        for (j = 1; j < pr[i]; ++j) {
          k = 2;
          y = j;
          while (y > 1) {
            if (y % k == 0)
              kol[k]--, y /= k;
            else
              ++k;
          }
        }
  for (i = sz; i >= 1; --i)
    for (j = 1; j <= kol[pr[i]]; ++j) cout << pr[i];
  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;
string n;
int y, k, i, x, len, len1, j, ans[100001];
int main() {
  cin >> len;
  cin >> n;
  for (i = 1; i <= len; ++i) {
    x = n[i - 1] - '0';
    for (j = 1; j <= x; ++j) {
      k = 2;
      y = j;
      while (y > 1) {
        if (y % k == 0)
          ans[++len1] = k, y /= k;
        else
          ++k;
      }
    }
  }
  bool used[1001];
  int pr[1001];
  int sz = 0;
  int kol[10001];
  memset(kol, 0, sizeof kol);
  sort(ans + 1, ans + len1 + 1);
  for (i = 1; i <= len1; ++i) {
    if (!used[ans[i]]) used[ans[i]] = true, pr[++sz] = ans[i];
    kol[ans[i]]++;
  }
  for (i = sz; i >= 1; --i)
    for (int l = 1; l <= kol[pr[i]]; ++l)
      if (kol[pr[i]] > 0)
        for (j = 1; j < pr[i]; ++j) {
          k = 2;
          y = j;
          while (y > 1) {
            if (y % k == 0)
              kol[k]--, y /= k;
            else
              ++k;
          }
        }
  for (i = sz; i >= 1; --i)
    for (j = 1; j <= kol[pr[i]]; ++j) cout << pr[i];
  return 0;
}

```