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;
int a[10];
int main() {
  int n;
  char c;
  scanf("%d", &n);
  memset(a, 0, sizeof(a));
  for (int i = 1; i <= n; i++) {
    scanf(" %c", &c);
    int t = c - '0';
    if (t == 1) a[1]++;
    if (t == 2) a[2]++;
    if (t == 3) a[3]++;
    if (t == 4) a[2] += 2, a[3]++;
    if (t == 5) a[5]++;
    if (t == 6) a[5]++, a[3]++;
    if (t == 7) a[7]++;
    if (t == 8) a[7]++, a[2] += 3;
    if (t == 9) a[7]++, a[3] += 2, a[2]++;
  }
  bool b = 0;
  for (int i = 9; i > 1; i--) {
    if (a[i] != 0 || b == 1) {
      b = 1;
      for (int j = 0; j < a[i]; j++) printf("%d", i);
    }
  }
  printf("\n");
  return 0;
}
