# Drazil and Factorial

Time Limit: 2 seconds

Memory Limit: 256 megabytes

## Description

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.

## Input

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

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

## Sample Input

Input41234Output33222Input3555Output555

## Sample Output

None

## Hint

In the first case,

None