Drazil is playing a math game with Varda.

Let's define <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7020b94c48be2ee5b8eeca05f379c8911bb0e7c4.png" style="max-width: 100.0%;max-height: 100.0%;"/> for positive integer *x* as a product of factorials of its digits. For example, <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/6784d861d9a724d0aeddefcb00b7d0c3442ae586.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

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. <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7020b94c48be2ee5b8eeca05f379c8911bb0e7c4.png" style="max-width: 100.0%;max-height: 100.0%;"/> = <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/aa57e017a6c74d06b0a54bc47e3f6990e5af38c1.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

Help friends find such number.
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.
n=int(input())
digits=list(map(int,input()))
print(digits)
countfact={2:0,3:0,5:0,7:0}
def fact(n):
    mydict={2:0,3:0,5:0,7:0}
    factor=[i for i in range(1,n+1)]
    for val in factor:
        if val==2:
            mydict[2]+=1
        elif val==3:
            mydict[3]+=1
        elif val==4:
            mydict[2]+=2
        elif val==5:
            mydict[5]+=1
        elif val==6:
            mydict[3]+=1
            mydict[2]+=1
        elif val==7:
            mydict[7]+=1
        elif val==8:
            mydict[2]+=3
        elif val==9:
            mydict[3]+=2
    return mydict
      
            
for digit in digits:
    tmp=fact(digit)
    
    for key in tmp.keys():
        countfact[key]+=tmp[key]

while countfact[2]!=0:
    if countfact[7]!=0:
        tmp=fact(7)
        print("7",end="")
        for key in tmp.keys():
            countfact[key]-=tmp[key]
    elif countfact[5]!=0:
        tmp=fact(5)
        print("5",end="")
        for key in tmp.keys():
            countfact[key]-=tmp[key]
    elif countfact[3]!=0:
        tmp=fact(3)
        print("3",end="")
        for key in tmp.keys():
            countfact[key]-=tmp[key]
    elif countfact[2]!=0:
        tmp=fact(2)
        print("2",end="")
        for key in tmp.keys():
            countfact[key]-=tmp[key]
            
