#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("sse4")
using namespace std;
int64_t dr8[] = {1, 1, 0, -1, -1, -1, 0, 1};
int64_t dc8[] = {0, 1, 1, 1, 0, -1, -1, -1};
int64_t dr4[] = {1, 0, 0, -1};
int64_t dc4[] = {0, 1, -1, 0};
int64_t gcd(int64_t a, int64_t b) {
  if (a % b == 0) return b;
  return gcd(b, a % b);
}
void inp(int64_t &x) {
  bool neg = false;
  register int64_t c;
  x = 0;
  c = getchar();
  if (c == '-') {
    neg = true;
    c = getchar();
  }
  for (; (c > 47 && c < 58); c = getchar()) x = (x << 1) + (x << 3) + c - 48;
  if (neg) x *= -1;
}
void solve();
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int64_t t = 1;
  for (int64_t i = 1; i <= t; i++) {
    solve();
    cout << endl;
  }
}
void solve() {
  int64_t i, n, j, m, k, l, t;
  cin >> n;
  string v[10];
  v[2] = "2";
  v[3] = "3";
  v[4] = "223";
  v[5] = "5";
  v[6] = "35";
  v[7] = "7";
  v[8] = "2227";
  v[9] = "3327";
  string ans;
  string s;
  cin >> s;
  for (i = 0; i < n; i++) {
    k = s[i] - '0';
    if (k > 1) {
      ans += v[k];
    }
  }
  sort((ans).begin(), (ans).end(), greater<int64_t>());
  cout << ans;
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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>
#pragma GCC optimize("O3")
#pragma GCC target("sse4")
using namespace std;
int64_t dr8[] = {1, 1, 0, -1, -1, -1, 0, 1};
int64_t dc8[] = {0, 1, 1, 1, 0, -1, -1, -1};
int64_t dr4[] = {1, 0, 0, -1};
int64_t dc4[] = {0, 1, -1, 0};
int64_t gcd(int64_t a, int64_t b) {
  if (a % b == 0) return b;
  return gcd(b, a % b);
}
void inp(int64_t &x) {
  bool neg = false;
  register int64_t c;
  x = 0;
  c = getchar();
  if (c == '-') {
    neg = true;
    c = getchar();
  }
  for (; (c > 47 && c < 58); c = getchar()) x = (x << 1) + (x << 3) + c - 48;
  if (neg) x *= -1;
}
void solve();
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int64_t t = 1;
  for (int64_t i = 1; i <= t; i++) {
    solve();
    cout << endl;
  }
}
void solve() {
  int64_t i, n, j, m, k, l, t;
  cin >> n;
  string v[10];
  v[2] = "2";
  v[3] = "3";
  v[4] = "223";
  v[5] = "5";
  v[6] = "35";
  v[7] = "7";
  v[8] = "2227";
  v[9] = "3327";
  string ans;
  string s;
  cin >> s;
  for (i = 0; i < n; i++) {
    k = s[i] - '0';
    if (k > 1) {
      ans += v[k];
    }
  }
  sort((ans).begin(), (ans).end(), greater<int64_t>());
  cout << ans;
}

```