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>
def factorial(n):
    res = 1
    for i in range(2, n + 1):
        res *= i
    return res

def F(x):
    res = 1
    while x > 0:
        dig = x % 10
        res *= factorial(dig)
        x //= 10
    return res

n = int(input())
a = int(input())

f_a = F(a)
f2 = F(2)
f3 = F(3)
f5 = F(5)
f7 = F(7)
res = ''

while f_a % f7 == 0:
    res += '7'
    f_a //= f7

while f_a % f5 == 0:
    res += '5'
    f_a //= f5

while f_a % f3 == 0:
    res += '3'
    f_a //= f3

while f_a % f2 == 0:
    res += '2'
    f_a //= f2

print(res)