Question: Use the sun and a magnifying glass to start a fire.
Option 0: On a sunny day, hold the glass above something that will burn easily.  Use a dry leaf of a piece of paper.  Move the glass so the suns rays focus on the paper.
Option 1: On a Tuesday day, hold the glass above something that will burn easily.  Use a dry leaf of a piece of paper.  Move the glass so the suns rays focus on the paper.
Answer: 0