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 addList(a, b):
    return [a[i] + b[i] for i in range(0, len(a))]


def isPrime(n):
    for i in range(2, n):
        if n % i is 0:
            return False
    return True


def Factorial(n):
    arr = [0,0,0,0,0,0,0,0,0,0]
    for i in range(2, n + 1):
        arr[i] = arr[i] + 1
    return arr


def calcArr(arr):
    # 9
    arr[3] = arr[3] + arr[9] * 2
    arr[9] = 0
    # 8
    arr[2] = arr[2] + arr[8] * 3
    arr[8] = 0
    # 7
    arr[2] = arr[2] - arr[7]
    arr[3] = arr[3] - arr[7]
    arr[2] = arr[2] - arr[7] * 2
    arr[5] = arr[5] - arr[7]
    arr[2] = arr[2] - arr[7]
    arr[3] = arr[3] - arr[7]
    # 6
    arr[2] = arr[2] + arr[6]
    arr[3] = arr[3] + arr[6]
    arr[6] = 0
    # 5
    arr[2] = arr[2] - arr[5]
    arr[3] = arr[3] - arr[5]
    arr[2] = arr[2] - arr[5] * 2
    # 4
    arr[2] = arr[2] + arr[4] * 2
    arr[4] = 0
    # 3
    arr[2] = arr[2] - arr[3]
    return arr
        

if __name__ == '__main__':
    input()
    str_ = str(input())
    arr = [0,0,0,0,0,0,0,0,0,0]

    for s in str_:
        arr = addList(arr, Factorial(int(s)))
    arr = calcArr(arr)

    res = []
    for i in range(1, 9):
        for j in range(0, arr[i]):
            res.append(str(i))

    res.sort(reverse=True)
    print("".join(res))
            
    
