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

ans = []
n = int(raw_input())
x = [int(j) for j in list(raw_input())]
for i in x:
    if i >= 2:
        ans += p[i]
ans.sort(reverse = True)
print ''.join([str(e) for e in ans])