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 fact(n):
    return 1 if n == 0 else n * fact(n - 1)


def main():
    n = raw_input()
    a = raw_input()

    primes = [0, 0, 0, 0]
    a = reduce(lambda x, y: x * y, map(lambda x: fact(int(x)), a))
    while a % 2 == 0:
        primes[0] += 1
        a /= 2
    while a % 3 == 0:
        primes[1] += 1
        a /= 3
    while a % 5 == 0:
        primes[2] += 1
        a /= 5
    while a % 7 == 0:
        primes[3] += 1
        a /= 7

    ans = ''
    while primes[3] > 0:
        ans += '7'
        primes[3] -= 1
        primes[2] -= 1
        primes[1] -= 2
        primes[0] -= 4
    while primes[2] > 0:
        ans += '5'
        primes[2] -= 1
        primes[1] -= 1
        primes[0] -= 3
    while primes[1] > 0:
        ans += '3'
        primes[1] -= 1
        primes[0] -= 1
    while primes[0] > 0:
        ans += '2'
        primes[0] -= 1

    print ans

main()
