(import (chicken io))

(define (read-num port)
  (let ((line (read-line port)))
    (if (eof-object? line)
	#f
	(string->number line))))

(define (part-1 port)
  (let loop ((total 0) (prev #f) (num (read-num port)))
    (define (next)
      (loop total num (read-num port)))
    (cond ((not num) total)
	  ((not prev) (next))
	  ((< prev num) (loop (add1 total) num (read-num port)))
	  (else (next)))))

(define (winsum vect)
  (apply + (vector->list vect)))

(define (part-2 port)
  (let loop ((i 0) (total 0) (window #(0 0 0)) (num (read-num port)))
    (if (not num)
	total
	(let ((old-val (winsum window)))
	  (vector-set! window (modulo i 3) num)
	  (if (and (> i 2) (< old-val (winsum window)))
	      (loop (add1 i) (add1 total) window (read-num port))
	      (loop (add1 i) total window (read-num port)))))))

(call-with-input-file "input"
  (lambda (p) (print (part-1 p))))

(call-with-input-file "input"
  (lambda (p) (print (part-2 p))))