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>
from math import factorial

n = int(raw_input())
x = raw_input()

p = [2, 3, 5, 7]
r = [0]*4


for c in x:
    d = int(c)
    if d == 0 or d == 1:
        continue

    f = factorial(d)

    for i, pr in enumerate(p):
        while f % pr == 0:

            f /= pr
            r[i] += 1


s = ""
s += "7"*r[3]
r[2]-=1*r[3]
r[1]-=2*r[3]
r[0]-=4*r[3]
s += "5"*r[2]
r[1]-=1*r[2]
r[0]-=3*r[2]
s += "3"*r[1]
r[0]-=1*r[1]
s += "2"*r[0]

print s
