I received an email from a recruiter, who then forwarded me to another recruiter. She explained the interview and hiring process:

I would go on-site (in my case, Google Pittsburgh) and have four interviews in one day, conducted on a whiteboard. I would also get lunch.

However, since I could only come later, I had lunch before all of my interviews, which were back-to-back. Each interview was 45 minutes, and the interviewer definitely guided me in the right direction at times.

Find the minimum number required to insert into a word to make it a palindrome.