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 Pascal (FPC 3.0.4) (judge verdict: Time Limit Exceeded)

program main;
var 
    n, i, ans : integer;
    prev : string;
    a : array[1..200000] of string;

procedure qs(l, r : integer);
var
    i, j : integer;
    p, temp : string;
begin
    if (l <= r) then begin
        i := l; j := l; p := a[r];
        while (i < r) do begin
            if (a[i] <= p) then begin 
                temp := a[i];
                a[i] := a[j];
                a[j] := temp;
                j := j + 1;
            end;
            i := i + 1;
        end;
        temp := a[j];
        a[j] := a[r];
        a[r] := temp;

        qs(l, j - 1);
        qs(j + 1, r);
    end;
end;

begin
    readln(n);
    for i := 1 to n do 
        readln(a[i]);
    
    qs(1, n);

    prev := a[1]; ans := 1;
    for i := 2 to n do
        if (a[i] <> prev) then begin
            ans := ans + 1;
            prev := a[i];
        end;

    writeln(ans);
end.