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>
#include <bits/stdc++.h>
using namespace std;
char s[20];
int ans[210];
int main() {
  int n;
  while (scanf("%d", &n) != EOF) {
    scanf("%s", s);
    int tot = 0;
    for (int i = 0; i < n; i++) {
      if (s[i] == '4') {
        ans[tot++] = 2;
        ans[tot++] = 2;
        ans[tot++] = 3;
      } else if (s[i] == '8') {
        ans[tot++] = 2;
        ans[tot++] = 2;
        ans[tot++] = 2;
        ans[tot++] = 7;
      } else if (s[i] == '6') {
        ans[tot++] = 3;
        ans[tot++] = 5;
      } else if (s[i] == '9') {
        ans[tot++] = 2;
        ans[tot++] = 3;
        ans[tot++] = 3;
        ans[tot++] = 7;
      } else if (s[i] != '0' && s[i] != '1') {
        ans[tot++] = s[i] - '0';
      }
    }
    sort(ans, ans + tot);
    for (int i = tot - 1; i >= 0; i--) printf("%d", ans[i]);
    puts("");
  }
  return 0;
}
