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 n;
char ch;
int q[111111];
int main() {
  scanf("%d", &n);
  int cnt = 0;
  for (int i = 1; i <= n; i++) {
    scanf(" %c", &ch);
    if (ch == '2') q[++cnt] = 2;
    if (ch == '3') q[++cnt] = 3;
    if (ch == '4') q[++cnt] = 2, q[++cnt] = 2, q[++cnt] = 3;
    if (ch == '5') q[++cnt] = 5;
    if (ch == '6') q[++cnt] = 5, q[++cnt] = 3;
    if (ch == '7') q[++cnt] = 7;
    if (ch == '8') q[++cnt] = 2, q[++cnt] = 2, q[++cnt] = 2, q[++cnt] = 7;
    if (ch == '9') q[++cnt] = 2, q[++cnt] = 3, q[++cnt] = 3, q[++cnt] = 7;
  }
  sort(q + 1, q + cnt + 1);
  for (int i = cnt; i; i--) printf("%d", q[i]);
  printf("\n");
  return 0;
}
