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 OCaml (4.10.0) (judge verdict: Accepted)

Scanf.scanf "%d" (fun n ->
    let s = Array.init n (fun _ -> Scanf.scanf " %s" (fun s -> s)) in
    Array.sort compare s;
    let rec loop i prev acc =
        if i = n then acc else
            if s.(i) = prev then loop (i + 1) prev acc
                            else loop (i + 1) s.(i) (acc + 1)
    in
    loop 1 s.(0) 1 |> Printf.printf "%d\n"
)