f = Array.new
f[1] = 1
f[2] = 1
i = 2

while f[i] <= 4000000
	i = i+1
	f[i] = f[i-1] + f[i-2]
end

j = 1
sum = 0
while j < i
	if f[j] % 2 == 0
		sum += f[j]
	end
	j = j+1
end

p sum