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 find(n,k): # finding k prime factor in n!
    ans=0
    i=1
    while n//(k**i) > 0 :
        ans+=(n//(k**i))
        i+=1
    return(ans)


def chebishev(n): # finding all prime factors in n!
    ans={2:0 , 3:0 , 5:0 , 7:0}
    for i in ans:
        ans[i]+=find(n,i)
    return(ans)


if __name__ == '__main__':

    n=int(input())
    s=input()

    q={2:0 , 3:0 , 5:0 , 7:0}

    for i in s:
        i=int(i)
        if i==0 or i==1 :
            continue
        y=chebishev(i)
        for i in y:
            q[i]+=y[i]

    t=sorted(q)
    t.reverse()

    answer=[]

    for i in t:
        while q[i]>0 :
            answer.append(str(i))
            o=chebishev(i)
            for j in o:
                q[j]-=o[j]
    
    answer.sort()
    answer.reverse()
    print(''.join(answer))



