Project Euler Problem 2

#! /usr/bin/ruby

def euler_2(n)
  f = 0
  l= 1
  numbers = []
  i = 0

  while i <= n
    i = f + l
    numbers << i if i % 2 == 0
    f = l
    l = i
  end

  puts "The sum is: #{numbers.inject(:+)}"
end

n = ARGV[0].to_i
euler_2 n