Clean Number String

In this problem, you are given a string which may contain digits, letters, spaces, and special characters. Your task is to extract all digit characters from the string and concatenate them to form a new number string. If no digit is found, output the text "Invalid Input".

More formally, given a string ( s ), compute the cleaned string ( S_{cleaned} ) as follows: [ S_{cleaned} = \bigoplus_{c \in s} \begin{cases} c, & \text{if } c \text{ is a digit}\ \epsilon, & \text{otherwise} \end{cases} ] If ( S_{cleaned} ) is empty, output "Invalid Input".

inputFormat

Input consists of a single line string read from standard input (stdin). The string may include letters, digits, spaces, and special characters.

outputFormat

Output a single line string to standard output (stdout) representing the concatenation of all the digit characters extracted from the input string. If no digit is found, output "Invalid Input".## sample

abcd!@#$%

Invalid Input