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 factor(n):
    d = 2
    fact = dict()
    while d * d <= n:
        if n % d == 0:
            fact[d] = 0
        while n % d == 0:
            fact[d] += 1
            n //= d
        d += 1
    if n > 1:
        fact[n] = 1
    return fact


n = int(input())
S = input()
strans = [""] * 10
strans[2] = "2"
strans[3] = "3"
strans[4] = "322"
strans[5] = "5"
strans[6] = "53"
strans[7] = "7"
strans[8] = "7" + "2" * 3
strans[9] = "7" + "3" * 2 + "2"
ans = ""
for c in S:
    ans += strans[int(c)]
ans = list(ans)
ans.sort(key=lambda x: -int(x))
print(''.join(ans))
