#include <bits/stdc++.h>
using namespace std;
const int inf = 0x20202020;
const long long mod = 1000000007;
const double eps = 1e-9;
const double pi = 3.1415926535897932384626;
const int DX[] = {1, 0, -1, 0}, DY[] = {0, 1, 0, -1};
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long powmod(long long a, long long b, long long mod) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
template <class X>
void debug(vector<X>& v) {
  for (int i = 0; i < v.size(); i++) cout << v[i] << " ";
  cout << endl;
}
int p[10], X[] = {7, 5, 3, 2};
int main() {
  int i, j, k, T, cas = 0;
  int n;
  cin >> n;
  string s;
  cin >> s;
  for (i = 0; i < ((int)(s).size()); i++) {
    int a = s[i] - '0', b, x;
    if (a <= 1) continue;
    for (j = 0; j < 4; j++) {
      b = a;
      x = 1;
      while (b) {
        x *= X[j];
        if (b / x == 0) break;
        p[j] += (b / x);
      }
    }
  }
  for (i = 0; i < 4; i++) {
    while (p[i]) {
      cout << X[i];
      p[i]--;
      for (j = i + 1; j < 4; j++) {
        int b = X[i];
        int x = 1;
        while (1) {
          x *= X[j];
          if (b / x == 0) break;
          p[j] -= (b / x);
        }
      }
    }
  }
  cout << endl;
  return 0;
}

### Prompt

Your challenge is to write 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;
const int inf = 0x20202020;
const long long mod = 1000000007;
const double eps = 1e-9;
const double pi = 3.1415926535897932384626;
const int DX[] = {1, 0, -1, 0}, DY[] = {0, 1, 0, -1};
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long powmod(long long a, long long b, long long mod) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
template <class X>
void debug(vector<X>& v) {
  for (int i = 0; i < v.size(); i++) cout << v[i] << " ";
  cout << endl;
}
int p[10], X[] = {7, 5, 3, 2};
int main() {
  int i, j, k, T, cas = 0;
  int n;
  cin >> n;
  string s;
  cin >> s;
  for (i = 0; i < ((int)(s).size()); i++) {
    int a = s[i] - '0', b, x;
    if (a <= 1) continue;
    for (j = 0; j < 4; j++) {
      b = a;
      x = 1;
      while (b) {
        x *= X[j];
        if (b / x == 0) break;
        p[j] += (b / x);
      }
    }
  }
  for (i = 0; i < 4; i++) {
    while (p[i]) {
      cout << X[i];
      p[i]--;
      for (j = i + 1; j < 4; j++) {
        int b = X[i];
        int x = 1;
        while (1) {
          x *= X[j];
          if (b / x == 0) break;
          p[j] -= (b / x);
        }
      }
    }
  }
  cout << endl;
  return 0;
}

```