Definition: In this task, you're given five sentences, numbered 1 through 5. Your job is to generate a title for the story that makes complete sense. The title must be short, with less than three words, use simple language, and include the main topic of the story.
Input: Sentence 1: Alexander wrote every day to his pen pal in Africa. Sentence 2: His pen pal had different views and it was very mind-opening. Sentence 3: They discussed all kinds of matter from politics to philosophy. Sentence 4: But one day his pen pal stopped writing. Sentence 5: Alexander didn't know why, but he was very disappointed.

Pen pal