#include <bits/stdc++.h>
using namespace std;
int n;
int s[10], g[15][5], w[10], l[10000], a[20], m[15][5];
char ch[20];
void pre() {
  s[1] = 2;
  s[2] = 3;
  s[3] = 5;
  s[4] = 7;
  for (int i = 2; i <= 9; ++i) {
    int k = i;
    for (int j = 1; j <= 4; ++j)
      if (k % s[j] == 0) {
        while (k % s[j] == 0 && k) {
          ++m[i][j];
          k /= s[j];
        }
      }
  }
  for (int i = 2; i <= 9; ++i) {
    for (int j = 1; j <= 4; ++j) g[i][j] = g[i - 1][j] + m[i][j];
  }
}
void init() {
  scanf("%d", &n);
  scanf("%s", ch);
  for (int i = 0; i < n; ++i) a[i + 1] = ch[i] - '0';
  sort(a + 1, a + 1 + n);
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= 4; ++j) w[j] += g[a[i]][j];
  for (int i = 4; i >= 1; --i)
    if (w[i]) {
      for (int j = 1; j < i; ++j) w[j] = w[j] - w[i] * g[s[i]][j];
      for (int j = 1; j <= w[i]; ++j) l[++l[0]] = s[i];
    }
  for (int i = 1; i <= l[0]; ++i) printf("%d", l[i]);
  printf("\n");
}
int main() {
  pre();
  init();
  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 n;
int s[10], g[15][5], w[10], l[10000], a[20], m[15][5];
char ch[20];
void pre() {
  s[1] = 2;
  s[2] = 3;
  s[3] = 5;
  s[4] = 7;
  for (int i = 2; i <= 9; ++i) {
    int k = i;
    for (int j = 1; j <= 4; ++j)
      if (k % s[j] == 0) {
        while (k % s[j] == 0 && k) {
          ++m[i][j];
          k /= s[j];
        }
      }
  }
  for (int i = 2; i <= 9; ++i) {
    for (int j = 1; j <= 4; ++j) g[i][j] = g[i - 1][j] + m[i][j];
  }
}
void init() {
  scanf("%d", &n);
  scanf("%s", ch);
  for (int i = 0; i < n; ++i) a[i + 1] = ch[i] - '0';
  sort(a + 1, a + 1 + n);
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= 4; ++j) w[j] += g[a[i]][j];
  for (int i = 4; i >= 1; --i)
    if (w[i]) {
      for (int j = 1; j < i; ++j) w[j] = w[j] - w[i] * g[s[i]][j];
      for (int j = 1; j <= w[i]; ++j) l[++l[0]] = s[i];
    }
  for (int i = 1; i <= l[0]; ++i) printf("%d", l[i]);
  printf("\n");
}
int main() {
  pre();
  init();
  return 0;
}

```