Segregate and Sort Characters

You are given a string that contains letters, digits, and special characters. Your task is to segregate the characters into three groups as follows:

• Letters: All alphabetic characters, which must be sorted in alphabetical order.
• Digits: All numeric characters, which must be sorted in ascending order.
• Special Characters: All other characters, which must remain in the same order as they appear in the input.

The final output should be a concatenation of the sorted letters, followed by the sorted digits, and then the special characters in their original order.

Note: If the input string is empty, output an empty string.

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Mathematically, if we denote the input string as \( S \), let \( L \) be the set of letters, \( D \) be the set of digits, and \( P \) be the sequence of special characters. Then the answer is:

\[ answer = sort(L) + sort(D) + P \]

inputFormat

The input consists of a single line containing a string \( S \) which may include letters, digits, and special characters.

outputFormat

Output the transformed string after segregating and sorting its characters as described above. The result is printed to stdout.

## sample

c3b1a2!x@z#4

abcxz1234!@#