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 factorize(n):
    divs = []
    div = 2
    while n != 1:
        if n % div == 0:
            n //= div
            divs.append(div)
        else:
            div += 1
    return divs


n = int(input())
num = input()
end_num = ''
f = []

for i in num:
    if i not in {'0', '1'}:
        for j in range(2, int(i) + 1):
            f += factorize(j)

f = sorted(f)[::-1]
while len(f) > 0:
    elem = f[0]
    for j in range(2, elem + 1):
        for k in factorize(j):
            f.pop(f.index(k))
    end_num += str(elem)

print(end_num)