Welcome to your interview.
The question is on your right: Invalid Parentheses Removal. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Write an algorithm to find and remove the minimum number of invalid parentheses to make an input string valid.