#include <bits/stdc++.h>
using namespace std;
int main() {
  long long fac[11];
  fac[0] = 1;
  for (int i = 0; i < 10; i++) fac[i + 1] = (i + 1) * fac[i];
  int len;
  long long n;
  cin >> len >> n;
  int cnt2 = 0, cnt3 = 0, cnt5 = 0, cnt7 = 0;
  for (; n; n /= 10) {
    long long f = fac[n % 10];
    for (; f % 7 == 0; f /= 7) cnt7++;
    for (; f % 5 == 0; f /= 5) cnt5++;
    for (; f % 3 == 0; f /= 3) cnt3++;
    for (; f % 2 == 0; f /= 2) cnt2++;
  }
  vector<int> ans;
  while (cnt7) {
    ans.push_back(7);
    long long f = fac[7];
    for (; f % 7 == 0; f /= 7) cnt7--;
    for (; f % 5 == 0; f /= 5) cnt5--;
    for (; f % 3 == 0; f /= 3) cnt3--;
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  while (cnt5) {
    ans.push_back(5);
    long long f = fac[5];
    for (; f % 5 == 0; f /= 5) cnt5--;
    for (; f % 3 == 0; f /= 3) cnt3--;
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  while (cnt3) {
    ans.push_back(3);
    long long f = fac[3];
    for (; f % 3 == 0; f /= 3) cnt3--;
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  while (cnt2) {
    ans.push_back(2);
    long long f = fac[2];
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  for (int i = 0; i < ans.size(); i++) cout << ans[i];
  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;
int main() {
  long long fac[11];
  fac[0] = 1;
  for (int i = 0; i < 10; i++) fac[i + 1] = (i + 1) * fac[i];
  int len;
  long long n;
  cin >> len >> n;
  int cnt2 = 0, cnt3 = 0, cnt5 = 0, cnt7 = 0;
  for (; n; n /= 10) {
    long long f = fac[n % 10];
    for (; f % 7 == 0; f /= 7) cnt7++;
    for (; f % 5 == 0; f /= 5) cnt5++;
    for (; f % 3 == 0; f /= 3) cnt3++;
    for (; f % 2 == 0; f /= 2) cnt2++;
  }
  vector<int> ans;
  while (cnt7) {
    ans.push_back(7);
    long long f = fac[7];
    for (; f % 7 == 0; f /= 7) cnt7--;
    for (; f % 5 == 0; f /= 5) cnt5--;
    for (; f % 3 == 0; f /= 3) cnt3--;
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  while (cnt5) {
    ans.push_back(5);
    long long f = fac[5];
    for (; f % 5 == 0; f /= 5) cnt5--;
    for (; f % 3 == 0; f /= 3) cnt3--;
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  while (cnt3) {
    ans.push_back(3);
    long long f = fac[3];
    for (; f % 3 == 0; f /= 3) cnt3--;
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  while (cnt2) {
    ans.push_back(2);
    long long f = fac[2];
    for (; f % 2 == 0; f /= 2) cnt2--;
  }
  for (int i = 0; i < ans.size(); i++) cout << ans[i];
  cout << endl;
  return 0;
}

```