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.
#!/usr/bin/env python3
n = int(input())
a = str(int(input()))
nb_digits = [0] * 10
for x in range(n):
    if a[x]=="0":
        continue
    elif a[x]=="1":
        continue
    elif a[x]=="2":
        nb_digits[2] += 1
    elif a[x]=="3":
        nb_digits[3] += 1
    elif a[x]=="4":
        nb_digits[2] += 2
        nb_digits[3] += 1
    elif a[x]=="5":
        nb_digits[5] += 1
    elif a[x]=="6":
        nb_digits[3] += 1
        nb_digits[5] += 1
    elif a[x]=="7":
        nb_digits[7] += 1
    elif a[x]=="8":
        nb_digits[2] += 3
        nb_digits[7] += 1
    elif a[x]=="9":
        nb_digits[2] += 3
        nb_digits[3] += 2
        nb_digits[7] += 7
nb_output = ""

for x in reversed(range(2, 8)):
    nb_output += str(x) * nb_digits[x]
print(nb_output)
