Definition: In this task, you're given five sentences, numbered 1 through 5, and two options a and b for possible titles for the story. Your job is to choose the title that better fits the story. Indicate your choice by 'a' or 'b'.
Input: Sentence 1: Jake and his neighbor tom lived in a desert area. Sentence 2: They had a friendly competition to save water. Sentence 3: Whoever had the highest bill at the end of the month bought lunch. Sentence 4: Jake decided to make a rain catching system to save water. Sentence 5: Jake didn't know that his neighbor had built a rain catcher too. Choices: a. Great Thinkers. b. Rock.

a