(define (fibonacci i)
	(let ((a 0) (b 1) (c 1))
	(define fib (lambda (n)
	(if (= n 0) c
		(begin (set! c (+ a b))
				(set! a b)
				(set! b c)
				(fib (- n 1))))))
	(fib  i)))

;c=a+b
;a=b
;b=c