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.

输入描述:

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.

输出描述:

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

备注:

In the first case,