Help me in solving PYPRACREAR1A problem

My issue

why 3 is not an answer

Learning course: Practice Python
Problem Link: CodeChef: Practical coding for everyone


Correct Answer:

Since the code is accepting input as input() - the default value is assumed to be a string.
Hence '1' and '2' will be treated as strings.
'1' + '2' will be treated as string concatenation.
Our output will be 12.