Working in Google momentarily, I have studied computer science for half of my life. While sitting in the cafetaria, having lunch with my colleagues, we are chatting about the new discovery of an asteroid called Talos 36. Suddenly, my phone buzzes for several times.

I am Alexander. Hopefully you are reading this message. We are EROS2009 and just crahsed our spacecraft on an asteriod in space. It seems that I am the only survivor right now. Losing the whole communication system, I tried to contact to the earth but you were the only reciever that had proper frequency to read and respond to me. Please help me!

Thank you, my friend. I ran out of all food and water 6 hours ago. There is no electricity and completely dark, but I have a lighter in my pocket. Whether do you think I should use it before moving around or save it later for emergency?

I agree. Otherwise, I can't see anything. You know, no sight, more dangers.

Jesus Christ. What a mess! Everything's everywhere. Door's also broken.

Wait a second! Thank god! I see a flashlight under those potatoes. Going to pick it up. Damn it. No batteries inside. Seems useless, but should I keep it anyway?

Sure, I don't think we can find batteries neither. Let's keep moving.

Here is the door, squeezed and blocked fully.