# sum of the even-valued terms in the Fibonacci sequence (starting with 1 and 2) whose values do not exceed four million

result = 0
current_number, next_number = 1 , 2

while current_number < 4000000
  if current_number % 2 == 0
    result += current_number
  end
  current_number, next_number = next_number, current_number + next_number
end

puts result