def fib_up_to(max)
  i1, i2 = 1, 1
  while i1 <= max
    yield i1 if block_given?
    i1, i2 = i2, i1 + i2
  end
end

puts "The Fibonacci sequence, up to 1000:"
fib_up_to(1000) { |f| print f, " " }
puts

sum = 0
fib_up_to(1000) { |f| sum += f }
puts "The sum of the Fibonacci numbers less than 1000 is #{sum}"