There were many prisoners at the prison where the man was sent. They were in prison because they had committed serious crimes. It was said that no one could leave there until he died once he was sent there.
An old prisoner said to the new prisoner "I killed more than ten people, and how many people did you kill?"
And then, the new prisoner said "No, I only broke windows at work in a rage".
The old prisoner was surprised. "Really? You only broke windows, didn't you? Where were you working then?"
The new prisoner answered "I worked in a submarine". "But the submarine has already sunk in the sea".