#include <bits/stdc++.h>
using namespace std;
int c[10];
void f(int a) {
  for (int i = 2; i <= a; ++i) {
    if (i == 2 || i == 3 || i == 5 || i == 7) c[i]++;
    if (i == 4) c[2] += 2;
    if (i == 6) c[2]++, c[3]++;
    if (i == 8) c[2] += 3;
    if (i == 9) c[3] += 2;
  }
}
int main() {
  int n;
  scanf("%d", &n);
  int a[n];
  for (int i = 0; i < n; ++i) {
    char j;
    scanf(" %c ", &j);
    a[i] = (int)j - (int)'0';
    f(a[i]);
  }
  int ans = 0;
  ans = c[2];
  ans -= c[5] * 2;
  ans -= c[7] * 2;
  while (c[2] != 0) {
    if (c[7] != 0) {
      printf("7");
      c[7]--;
      c[3]--;
      c[2]--;
      c[5]--;
      c[2]--;
      c[2]--;
      c[3]--;
      c[2]--;
    } else if (c[5] != 0) {
      printf("5");
      c[5]--;
      c[2]--;
      c[2]--;
      c[3]--;
      c[2]--;
    } else if (c[3] != 0) {
      printf("3");
      c[3]--;
      c[2]--;
    } else {
      printf("2");
      c[2]--;
    }
  }
  printf("\n");
  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 c[10];
void f(int a) {
  for (int i = 2; i <= a; ++i) {
    if (i == 2 || i == 3 || i == 5 || i == 7) c[i]++;
    if (i == 4) c[2] += 2;
    if (i == 6) c[2]++, c[3]++;
    if (i == 8) c[2] += 3;
    if (i == 9) c[3] += 2;
  }
}
int main() {
  int n;
  scanf("%d", &n);
  int a[n];
  for (int i = 0; i < n; ++i) {
    char j;
    scanf(" %c ", &j);
    a[i] = (int)j - (int)'0';
    f(a[i]);
  }
  int ans = 0;
  ans = c[2];
  ans -= c[5] * 2;
  ans -= c[7] * 2;
  while (c[2] != 0) {
    if (c[7] != 0) {
      printf("7");
      c[7]--;
      c[3]--;
      c[2]--;
      c[5]--;
      c[2]--;
      c[2]--;
      c[3]--;
      c[2]--;
    } else if (c[5] != 0) {
      printf("5");
      c[5]--;
      c[2]--;
      c[2]--;
      c[3]--;
      c[2]--;
    } else if (c[3] != 0) {
      printf("3");
      c[3]--;
      c[2]--;
    } else {
      printf("2");
      c[2]--;
    }
  }
  printf("\n");
  return 0;
}

```