# Each new term in the Fibonacci sequence is generated by adding the previous two terms. 
# By starting with 1 and 2, the first 10 terms will be:
# 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
# Find the sum of all the even-valued terms in the sequence which do not exceed four million.

def fib(n)
	return n if (0..1).include? n
	fib(n-1) + fib(n-2)
end

# i is an iterator, start at 2 because the problem says to start with 1 & 2
fibs = Array.new
i = 2
f = 0
while f < 4000000
	f = fib(i)
	if f%2==0
		fibs << f
	end
	i = i + 1
end

#sum up the numbers in the array, then output the sum
ret = fibs.inject(0) {|x,n| x+n}
print "#{ret} is the sum \n"

#another way
ret2 = 0
f2 = 0
i2 = 2
while f2 < 4000000
	f2 = fib(i2)
	if f2%2==0
		ret2 = ret2 + f2
	end
	i2 = i2 + 1
end

print "#{ret2} is the sum\n"