#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int n;
long long a;
int s[10];
void deal(int a) {
  for (int i = a; i >= 2; i--) {
    s[i]++;
  }
  return;
}
void print(int a) {
  if (a == 2) {
    s[2]--;
    cout << 2;
  }
  if (a == 3) {
    s[3]--;
    s[2]--;
    cout << 3;
  }
  if (a == 4) {
    s[2] -= 3;
    s[3]--;
    cout << 4;
  }
  if (a == 5) {
    s[2] -= 3;
    s[3]--;
    s[5]--;
    cout << 5;
  }
  if (a == 6) {
    s[2] -= 4;
    s[3] -= 2;
    s[5]--;
    cout << 6;
  }
  if (a == 7) {
    s[2] -= 4;
    s[3] -= 2;
    s[5]--;
    s[7]--;
    cout << 7;
  }
}
int main() {
  scanf("%d", &n);
  scanf("%lld", &a);
  while (a) {
    deal(a % 10);
    a /= 10;
  }
  s[3] += s[9] * 2;
  s[2] += s[8] * 3;
  s[3] += s[6];
  s[2] += s[6];
  s[2] += s[4] * 2;
  n = s[7];
  for (int i = 1; i <= n; i++) {
    print(7);
  }
  n = s[5];
  for (int i = 1; i <= n; i++) {
    print(5);
  }
  n = s[3];
  for (int i = 1; i <= n; i++) {
    print(3);
  }
  n = s[2];
  for (int i = 1; i <= n; i++) {
    print(2);
  }
  cout << endl;
  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;
const int mod = 1e9 + 7;
int n;
long long a;
int s[10];
void deal(int a) {
  for (int i = a; i >= 2; i--) {
    s[i]++;
  }
  return;
}
void print(int a) {
  if (a == 2) {
    s[2]--;
    cout << 2;
  }
  if (a == 3) {
    s[3]--;
    s[2]--;
    cout << 3;
  }
  if (a == 4) {
    s[2] -= 3;
    s[3]--;
    cout << 4;
  }
  if (a == 5) {
    s[2] -= 3;
    s[3]--;
    s[5]--;
    cout << 5;
  }
  if (a == 6) {
    s[2] -= 4;
    s[3] -= 2;
    s[5]--;
    cout << 6;
  }
  if (a == 7) {
    s[2] -= 4;
    s[3] -= 2;
    s[5]--;
    s[7]--;
    cout << 7;
  }
}
int main() {
  scanf("%d", &n);
  scanf("%lld", &a);
  while (a) {
    deal(a % 10);
    a /= 10;
  }
  s[3] += s[9] * 2;
  s[2] += s[8] * 3;
  s[3] += s[6];
  s[2] += s[6];
  s[2] += s[4] * 2;
  n = s[7];
  for (int i = 1; i <= n; i++) {
    print(7);
  }
  n = s[5];
  for (int i = 1; i <= n; i++) {
    print(5);
  }
  n = s[3];
  for (int i = 1; i <= n; i++) {
    print(3);
  }
  n = s[2];
  for (int i = 1; i <= n; i++) {
    print(2);
  }
  cout << endl;
  return 0;
}

```