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 = {2:0,3:0,5:0,7:0}
a = [(1,0,0,0),(1,1,0,0),(3,1,0,0),(3,1,1,0),(4,2,1,0),(4,2,1,1),(7,2,1,1),(7,4,1,1)]

n = input()
s = list(raw_input())
for i in range(n):
    s[i] = int(s[i])
    if s[i] == 0 or s[i] == 1:
        continue
    else:
        d[2] += a[s[i]-2][0]
        d[3] += a[s[i] - 2][1]
        d[5] += a[s[i] - 2][2]
        d[7] += a[s[i] - 2][3]


ans = '7'*d[7] + '5'*(d[5]-d[7]) + '3'*(d[3] - (d[5]-d[7]) - 2*d[7]) + '2'*(d[2] - (d[3] - (d[5]-d[7]) - 2*d[7]) - 3*(d[5]-d[7]) - 4*d[7])

print ans
