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>
d = {
    2: {2:1},
    3: {2:1, 3:1},
    4: {2:3, 3:1},
    5: {2:1, 3:1, 4:1, 5:1},
    6: {2:2, 3:2, 4:1, 5:1},
    7: {2:1, 3:1, 4:1, 5:1, 6:1, 7:1},
    8: {2:4, 3:1, 4:1, 5:1, 6:1, 7:1},
    9: {2:4, 3:3, 4:1, 5:1, 6:1, 7:1}
}
e = {2:0, 3:0, 4:0, 5:0, 6:0, 7:0}
input()
l = map(lambda x: int(x), iter(input().strip()))
for i in l:
    if i > 1:
        for k,v in d[i].items():
            e[k] += v
o = ''
for i in reversed(range(2,8)):
    while e[i] > 0:
        for k in e:
            e[k] -= 1
        o += str(i)
print(o)