Description:
Drazil is playing a math game with Varda.
Let's define $$\mathbf{F}(x)$$ for positive integer x as a product of factorials of its digits. For example, $$F(135) = 1! * 3! * 5! = 720$$.
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. $$\mathbf{F}(x)$$ = $$\mathbf{F}(a)$$.
Help friends find such number.
Input Format:
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 Format:
Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.
Note:
In the first case, $$F(1234) = 1! * 2! * 3! * 4! = 288 = F(3322)$$