isolated (20-n1)

(define (isolated )
  (define in (open-input-file "matrix.txt"))
(define (iter i Nstr)
  (define line (read-line in))
  (if (equal? line eof) i
    (iter (+(help (string->list line) Nstr 1) i) (+ 1 Nstr) )))
  (iter 0 1))
(define (help lst Nstr i)
  (cond
    ( (equal? (car lst) #\return ) 1)
    ( (equal? Nstr i) (help (cdr lst) Nstr (+ i 1)))
    ( (equal? (car lst) #\1) 0)
    ( (equal? (car lst) #\space) (help (cdr lst) Nstr i))
    (else (help (cdr lst) Nstr (+ i 1)))))