Problem:
Score : 300 points

Problem Statement

You drew lottery N times. In the i-th draw, you got an item of the kind represented by a string S_i.

How many kinds of items did you get?

Constraints

1 \leq N \leq 2\times 10^5

S_i consists of lowercase English letters and has a length between 1 and 10 (inclusive).

Input

Input is given from Standard Input in the following format:

N
S_1
:
S_N

Output

Print the number of kinds of items you got.

Sample Input 1

3
apple
orange
apple

Sample Output 1

2

You got two kinds of items: apple and orange.

Sample Input 2

5
grape
grape
grape
grape
grape

Sample Output 2

1

Sample Input 3

4
aaaa
a
aaa
aa

Sample Output 3

4

Solution in Common Lisp (SBCL 2.0.3) (judge verdict: Time Limit Exceeded)

(defun compressor (function lst) ;圧縮関数 collectorよりはちょっと早い
  (cond ((not lst) nil)
        ((not (cdr lst)) (list (cons (car lst) 1)))
        (t
         (let* ((ll (mapcar function lst (cdr lst)))
                (mem 0)
                (lf nil))
           (mapcar (lambda (k)
                     (if (not k) (push mem lf))
                     (incf mem)) ll)
           (push (1- (length lst)) lf)
           (setf lf (reverse lf))
           (mapcar #'cons
                   (mapcar (lambda (k) (elt lst k)) lf)
                   (cons (car lf) (mapcar (lambda (a b)
                                            (abs (- a b))) lf (cdr lf))))))))
(let* ((n (read))
       (m (loop :repeat n :collect (read-line))))
  (princ (length (compressor #'string= (sort m #'string<)))))