challenges/e2/e2.rb

#!/usr/bin/ruby

def sum(last, current, sum)
	if current >= 4000000
		return sum
	end
	if current % 2 == 0
		sum += current
	end
	tmp = current
	current += last
	last = tmp
	sum(last, current, sum)
end

puts sum(0, 1, 0)