Sathwik
I believe this post should help, you can do this via Javascript and store it back in embedded data
left/right substring extraction functions from piped text? — XM Community (qualtrics.com)
Hope it helps!

I want to achieve it through math operations only, not through java script.

Sathwik
As mentioned on this support page Math operations do not allow you to strip the string.
"Math operations allow you to create custom values with each response. For example, you can create a function that calculates a formula using scoring for individual participants. Math operations can be performed in the survey flow, within a question, or choice text."
Hence, if you need to achieve something like that as far as I know JS is the route.
Hope it helps!