### Problem Statement

You are given two Strings, number and digits. Each String contains only digits between 1 and 9, inclusive. For each occurrence of a digit in digits, you must remove a single occurrence of that digit from number. Your goal is to end up with the largest possible remaining number after all the necessary digits are removed. Return this number as a String.

### Definition

 Class: RemovingDigits Method: maxNumber Parameters: String, String Returns: String Method signature: String maxNumber(String number, String digits) (be sure your method is public)

### Constraints

-number will contain between 1 and 50 characters, inclusive.
-digits will contain between 0 and n-1 characters, inclusive, where n is the number of characters in number.
-Each character in number and digits will be a non-zero digit ('1'-'9').
-The number of occurrences of each digit in number will be greater than or equal to the number of occurrences of that digit in digits.

### Examples

0)

 `"12345"` `"513"`
`Returns: "24"`
 If we remove the digits '5', '3', '1' we get the number 24.
1)

 `"112352"` `"1123"`
`Returns: "52"`
 There are two choices. We can either get a "25" or a "52". The largest is "52".
2)

 `"123456654321"` `"612534"`
`Returns: "654321"`
 Removing the first half of our number gives us the maximum result.
3)

 `"654321123456"` `"612534"`
`Returns: "654321"`
 Removing the last half of our number gives us the maximum result.
4)

 `"2654982765982365"` `"2345978"`
`Returns: "698265265"`

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=8721

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=12168&pm=8721

asal1

#### Testers:

PabloGilberto , Olexiy , Andrew_Lazarev , ivan_metelsky

#### Problem categories:

Greedy, Search, String Manipulation