I am a stone, and I am rolling down a mountaintop. Right now, I am a very small stone, but I want grow my [Mass] and [Diameter] to become the biggest stone of all!

  Luckily I can grow bigger by hitting people on the head really hard.

  This book's true home is on another platform. Check it out there for the real experience.

  Wish me luck!

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  Linkie link link.

  math for it. There are a bunch of chapters out.