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 c[10], f[10];
int main() {
  f[0] = 1;
  for (int i = 1; i < 10; ++i) f[i] = i * f[i - 1];
  int n;
  scanf("%d%s", &n, s);
  for (int i = 0; i < n; ++i) {
    int d = f[s[i] - '0'];
    for (int k = 2; k * k <= d; ++k)
      if (d % k == 0) {
        int cnt = 0;
        for (; d % k == 0; ++cnt, d /= k)
          ;
        c[k] += cnt;
      }
    if (d > 1) ++c[d];
  }
  while (c[7]) {
    c[2] -= 4, c[3] -= 2, c[5] -= 1, c[7] -= 1;
    printf("7");
  }
  while (c[5]) {
    c[2] -= 3, c[3] -= 1, c[5] -= 1;
    printf("5");
  }
  while (c[3]) {
    c[2] -= 1, c[3] -= 1;
    printf("3");
  }
  while (c[2]) {
    c[2] -= 1;
    printf("2");
  }
  return 0;
}
