Time Limit: 2 seconds
Memory Limit: 256 megabytes
Drazil is playing a math game with Varda.
Let's define for positive integer x as a product of factorials of its digits. For example, .
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. = .
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.
Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.