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>
import sys

num_digits = int(sys.stdin.readline())

line = sys.stdin.readline().strip()

numa = {}
numa[2] = 0
numa[3] = 0
numa[5] = 0
numa[7] = 0

for x in range(num_digits):
    for z in range(2, int(line[x])+1):
        for y in numa.keys():
            while z != 0:
                if z % y != 0:
                    break
                else:
                    numa[y] += 1
                    z = z / y

# 7 6 5 4 3 2
numa[2] -= numa[7]
numa[3] -= numa[7]

numa[5] -= numa[7]

numa[2] -= 2*numa[7]

numa[3] -= numa[7]

numa[2] -= numa[7]

# 4 3 2 
numa[2] -= 2 * numa[5]
numa[3] -= numa[5]
numa[2] -= numa[5]

#2
numa[2] -= numa[3]

result_str = []    
for x in sorted(numa.keys(), reverse=True):
    if numa[x] != 0:
        for y in range(numa[x]):
            result_str.append(str(x))


print ''.join(result_str)
