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>
def main():
    line = raw_input()
    line = raw_input()

    x = fragment(line)

    x = factorize_all(x)

    x.sort()
    x.reverse()

    print rebuild_number(x)


def rebuild_number(x):
    b = 0
    for a in x:
        b *= 10
        b += a

    return b


def fragment(line):
    x = []

    for t in line:
        if t != '0' and t != '1':
            x.append(int(t))

    return x


def factorize_all(x):
    u = []
    for a in x:
        u.extend(factorize(a))

    return u


def factorize(a):
    if a == 4:
        return [3, 2, 2]
    elif a == 6:
        return [3, 5]
    elif a == 8:
        return [7, 2, 2, 2]
    elif a == 9:
        return [3, 3, 2, 7]
    else:
        return [a]

main()