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>
num_map = dict()
num_map["0"] = []
num_map["1"] = []
num_map["2"] = ["2"]
num_map["3"] = ["3"]
num_map["4"] = ["3", "2", "2"]
num_map["5"] = ["5"]
num_map["6"] = ["5", "3"]
num_map["7"] = ["7"]
num_map["8"] = ["7", "2", "2", "2"]
num_map["9"] = ["7", "3", "3", "2"]

n = raw_input()
str_list = map(str, list(raw_input()))
ans = []
for i in str_list:
    ans.extend(num_map[i])
ans.sort(reverse = True)
print "".join(ans)
