516_A. Drazil and Factorial
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>
```python

def add(x, i):
    if i == 1:
        pass
    if i == 2:
        x.append(2)
    if i == 3:
        x.append(3)
    if i == 4:
        x.append(2)
        x.append(2)
        x.append(3)
    if i == 5:
        x.append(5)
    if i == 6:
        x.append(5)
        x.append(3)
    if i == 7:
        x.append(7)
    if i == 8:
        x.append(7)
        x.append(2)
        x.append(2)
        x.append(2)
    if i == 9:
        x.append(7)
        x.append(2)
        x.append(3)
        x.append(3)


def work(a):
    x = []
    for i in a:
        add(x, int(i))
    x.sort(reverse=True)
    print(''.join([str(c) for c in x]))



input()
work(input())

```