From: Peter Hickman <peterhickman386@...>
Date: 2010-07-13T19:25:49+09:00
Subject: Re: Why do I get undefined method?

year = gets

returns a string but your function requires a fixnum

so try

year = gets.to_i

this is one of the few times that you have to explicitly convert
types. It doesn't happen alot in ruby and each time it catches me out