;; -*- coding: utf-8 -*-
(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx OPT
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) (read s nil nil t))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
;; Should we do this with UNWIND-PROTECT?
(defmacro with-buffered-stdout (&body body)
  "Buffers all outputs to *STANDARD-OUTPUT* in BODY and flushes them to
*STANDARD-OUTPUT* after BODY has been done (without error). Note that only
BASE-CHAR is allowed."
  (let ((out (gensym)))
    `(let ((,out (make-string-output-stream :element-type 'base-char)))
       (let ((*standard-output* ,out))
         ,@body)
       (write-string (get-output-stream-string ,out)))))

(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  (declare #.OPT)
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setf minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48)
                              (* 10 (the (integer 0 #.(floor most-positive-fixnum 10)) result))))
              (return (if minus (- result) result))))))))

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defconstant +inf+ most-positive-fixnum)
(define-modify-macro minf (new-value) min)

(declaim (inline warshall-floyd!))
(defun warshall-floyd! (matrix)
  (let ((n (array-dimension matrix 0)))
    (dotimes (k n)
      (let ((base-k (array-row-major-index matrix k 0)))
        (dotimes (i n)
          (let ((base-i (array-row-major-index matrix i 0)))
            (dotimes (j n)
              (minf (row-major-aref matrix (+ base-i j))
                    (+ (row-major-aref matrix (+ base-i k))
                       (row-major-aref matrix (+ base-k j)))))))))))

(defun main ()
  (declare #.OPT)
  (let* ((n (read))
         (m (read))
         (l (read))
         (adj (make-array '(300 300) :element-type 'uint62 :initial-element +inf+)))
    (declare (uint31 n m l))
    (dotimes (i m)
      (let ((a (- (read-fixnum) 1))
            (b (- (read-fixnum) 1))
            (c (read-fixnum)))
        (setf (aref adj a b) c
              (aref adj b a) c)))
    (warshall-floyd! adj)
    (dotimes (i n)
      (dotimes (j n)
        (if (> (aref adj i j) l)
            (setf (aref adj i j) +inf+)
            (setf (aref adj i j) 1))))
    (warshall-floyd! adj)
    (with-buffered-stdout
      (dotimes (_ (the uint32 (read)))
        (let* ((start (- (read-fixnum) 1))
               (goal (- (read-fixnum) 1)))
          (println
           (if (= +inf+ (aref adj start goal))
               -1
               (- (aref adj start goal) 1))))))))

#-swank (main)


Measured memory_bytes: 30564