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>
map = {
        2: [2],
        3: [3],
        4: [2, 2, 3],
        5: [5],
        6: [3, 5],
        7: [7],
        8: [2, 2, 2, 7],
        9: [3, 3, 2, 7]
}

def __a__(a):
    for digit in a:
        if digit == 0 or digit == 1:
            continue

        for d in map[digit]:
            yield str(d)

if __name__ == '__main__':
    n = int(raw_input())
    a = [int(c) for c in raw_input()]

    print ''.join(sorted(__a__(a), reverse=True))
