Task: Select the longest sentence in terms of the number of words in the paragraph, output the sentence index.
input: (1) So what’s Black Friday again? (2) If we’re being honest, Black Friday is kind of like our Super Bowl. (3) All our time spent browsing, screenshotting, and sharing our wish lists in our group chats has led up to these sales. (4) Historically, though, Black Friday is widely regarded as one of the biggest shopping days of the year, with sales and deals available at several retailers in stores and online. (5) Black Friday has become more than scoring TVs and electronics.
output: 4