def fib_rec (number)
	if number == 0
		return number
	elsif (number == 1) || (number == 2)
		return 1
	end
	fib_rec(number - 1) + fib_rec(number - 2)
end

def fib_non_rec (number)
	a = 0
	b = 1
	while number != 0
		a, b = b, a + b
		number -= 1
	end
	a
end

puts fib_non_rec(10) == fib_rec(10)

# => true