Rearrange Characters

Given a string S consisting of lowercase letters and digits, rearrange the string so that all the lowercase letters appear before any digit. The relative order of the letters and the digits should remain unchanged.

Input Constraints: The string S will contain only lowercase letters and digits, with no spaces. Its length can be up to 1000 characters.

Example:
For S = "a1b2c3", the expected output is "abc123".

inputFormat

The input consists of a single line containing the string S.

outputFormat

Output the rearranged string where all letters appear before the digits.

a1b2c3

abc123