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 C (GCC 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct node {
	struct node *left;
	struct node *right;
	char word[11];
};

struct node *
insert(struct node *p, char *word)
{
	int cmp;
	if (p == NULL) {
		p = (struct node *)malloc(sizeof(struct node));
		p->left = (struct node *)NULL;
		p->right = (struct node *)NULL;
		strcpy(p->word, word);
		return p;
	} else {
		cmp = strcmp( word, p->word);
		if ( cmp == 0) {
			/* already exist */
			return p;
		} else if (cmp < 0) {
			p->left = insert(p->left, word);
			return p;
		} else if (cmp > 0) {
			p->right = insert(p->right, word);
			return p;
		} else {
			printf("This case is not exist");
		}
	}
}

int countNode(struct node *p, int n)
{
	n++;
	if (p->left != NULL)
		n =	countNode(p->left, n);
	if (p->right != NULL)
		n = countNode(p->right, n);
	return n;
}

int main()
{
	int i, n, ret;
	int N;
	char **S;
	char **Depot;
	int hit;
	struct node *root = (struct node *)NULL;
	
	ret = scanf("%d", &N);
	
	S = (char **) malloc(sizeof(char *)*N);
	for (i = 0;i < N; i++) {
		S[i] = (char *) malloc(sizeof(char)*11);
	}

	for (i = 0; i < N; i++){
		ret = scanf("%s\n", S[i]);
		root = insert(root, S[i]);
	}
	n = countNode(root, 0);
	printf("%d\n",n);
	fflush(stdout);
	free(S);
	return EXIT_SUCCESS;
}