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.
a=int(input());b=input();k=["",""];z=[];o=""
for i in range(2,10):
    j=2;r=i
    while(r!=1 and j<4):
        if r%j==0:r//=j;z+=[j]
        else:j+=1
    if r==i:k+=[str(i)]
    else:
        k+=["3"*min(z.count(3),z.count(2))+"2"*(z.count(2)-min(z.count(3),z.count(2)))+"3"*min(str(k[-1]).count("2"),z.count(3)-min(z.count(3),z.count(2)))]
        p=[2]*min(str(k[-2]).count("2"),z.count(3)-min(z.count(3),z.count(2)))
        for i in str(k[-2]):
            if int(i) in p:p.remove(int(i))
            else:k[-1]+=str(i)
    z=[]
gh=""
for i in b:gh+=k[int(i)]
gh.replace(" ","")
print(gh)



