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
input = sys.stdin.readline
sys.setrecursionlimit(10**6)


############ ---- Input Functions ---- ############
def in_int():
    return (int(input()))


def in_list():
    return (list(map(int, input().split())))


def in_str():
    s = input()
    return (list(s[:len(s) - 1]))


def in_ints():
    return (map(int, input().split()))

n  = in_int()

m = [[], [], [2], [3], [3,2,2], [5], [5,3], [7], [7,2,2,2], [7,3,3,2]]
fact = [1]*10

for i in range(1,10):
    fact[i] = fact[i-1]*i

a = in_str()

count = [0]*10
for xx in a:
    nn = int(xx)
    for ll in m[nn]:
        count[ll]  +=1


for i in range(9,1,-1):
    for j in range(count[i]):
        print(i,end='')

