#include <bits/stdc++.h>
using namespace std;
const string problemName = "";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
const int INF = (1LL << 31) - 1;
const long long int LINF = (1LL << 62) - 1;
const int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};
const int MOD = (int)(1e9) + 7;
const int NMAX = 100000 + 5;
const int MMAX = 100000 + 5;
const int KMAX = 100000 + 5;
const int PMAX = 100000 + 5;
const int LMAX = 100000 + 5;
const int VMAX = 100000 + 5;
int N;
long long int A;
vector<int> V;
void desc(int c) {
  int i, j, k;
  if (c == 2 || c == 3 || c == 5 || c == 7) V.push_back(c);
  if (c == 4) {
    V.push_back(3);
    V.push_back(2);
    V.push_back(2);
  }
  if (c == 6) {
    V.push_back(5);
    V.push_back(3);
  }
  if (c == 8) {
    V.push_back(7);
    V.push_back(2);
    V.push_back(2);
    V.push_back(2);
  }
  if (c == 9) {
    V.push_back(7);
    V.push_back(3);
    V.push_back(3);
    V.push_back(2);
  }
}
int main() {
  int c;
  scanf("%d", &N);
  scanf("%lld", &A);
  while (A) {
    c = A % 10;
    A /= 10;
    if (c > 1) desc(c);
  }
  sort(V.rbegin(), V.rend());
  for (auto x : V) printf("%d", x);
  return 0;
}

### Prompt

Your task is to create 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 string problemName = "";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
const int INF = (1LL << 31) - 1;
const long long int LINF = (1LL << 62) - 1;
const int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};
const int MOD = (int)(1e9) + 7;
const int NMAX = 100000 + 5;
const int MMAX = 100000 + 5;
const int KMAX = 100000 + 5;
const int PMAX = 100000 + 5;
const int LMAX = 100000 + 5;
const int VMAX = 100000 + 5;
int N;
long long int A;
vector<int> V;
void desc(int c) {
  int i, j, k;
  if (c == 2 || c == 3 || c == 5 || c == 7) V.push_back(c);
  if (c == 4) {
    V.push_back(3);
    V.push_back(2);
    V.push_back(2);
  }
  if (c == 6) {
    V.push_back(5);
    V.push_back(3);
  }
  if (c == 8) {
    V.push_back(7);
    V.push_back(2);
    V.push_back(2);
    V.push_back(2);
  }
  if (c == 9) {
    V.push_back(7);
    V.push_back(3);
    V.push_back(3);
    V.push_back(2);
  }
}
int main() {
  int c;
  scanf("%d", &N);
  scanf("%lld", &A);
  while (A) {
    c = A % 10;
    A /= 10;
    if (c > 1) desc(c);
  }
  sort(V.rbegin(), V.rend());
  for (auto x : V) printf("%d", x);
  return 0;
}

```