Process Backspaces in a String

You are given a string s that contains lowercase letters and the character '#' which represents a backspace. Your task is to process the string by interpreting each '#' as a backspace operation that deletes the character immediately before it. If there is no character to delete, the '#' does nothing. Finally, output the resulting string after all backspace operations have been applied.

For example, given the string "abc#d##", the final string would be "a".

Note: The backspace operation can be thought of in terms of stack operations where a push occurs for each regular character and a pop occurs whenever a '#' is encountered (provided the stack is not empty). In LaTeX, you might express the core idea as:

$$ S = \text{process}(s) $$

inputFormat

The input consists of a single line containing the string s which consists of lowercase letters and the '#' character representing a backspace.

You should read from standard input (stdin).

outputFormat

Output the processed string after applying all the backspace operations. Write your result to standard output (stdout).

a#