(module sieve mzscheme

  (define (main args)
    (let ((n (if (= (vector-length args) 0)
		 1
		 (string->number (vector-ref args 0))))
	  (count 0)
	  (flags (make-vector 8192)))
      (let loop ((iter n))
	(if (> iter 0)
	    (begin
	      (do ((i 0 (+ i 1))) ((>= i 8192)) (vector-set! flags i #t))
	      (set! count 0)
	      (do ((i 2 (+ 1 i)))
		  ((>= i 8192))
		(if (vector-ref flags i)
		    (begin
		      (do ((k (+ i i) (+ k i)))
			  ((>= k 8192))
			(vector-set! flags k #f))
		      (set! count (+ 1 count)))))
	      (loop (- iter 1)))))
      (display "Count: ") (display count) (newline)))

  (main (current-command-line-arguments)))