#lang racket

(with-input-from-file "../input/01"
  (lambda ()
    (for/fold ([cnt 0]
               [last null]
               #:result cnt)
              ([line (in-lines)])
      (let ([num (string->number line)])
        (if (< (length last) 3)
          (values cnt (append last (list num)))
          (values
            (if (> num (car last))
              (+ cnt 1)
              cnt)
            (append (cdr last) (list num))))))))