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 Rust (1.42.0) (judge verdict: Wrong Answer)

fn is_exsits_word(word :&String, dict :&Vec<String>) -> bool
{
    false
}

const NUM_OF_AB :usize = 26;
const A_INDEX   :usize = 97;
fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let num_of_prizes :usize = s.trim().parse::<usize>().ok().unwrap();

    let mut prizes :Vec<Vec<String>> = Vec::new();
    for _ in 0..NUM_OF_AB {
        prizes.push(Vec::new());
    }
    for _ in 0..num_of_prizes {
        let mut s1 = String::new();
        std::io::stdin().read_line(&mut s1).ok();

        let initial = s1.chars().next().unwrap();
        let ini_idx = (initial as usize) - A_INDEX;
        if  !is_exsits_word(&s1, &prizes[ini_idx])  {
            prizes[ini_idx].push(s1);
        }
    }
    /*
    for i in 0..prizes.len() {
        println!("{}", prizes[i]);
    }
    */
    let mut num_of_kind :u32 = 0;
    for i in 0..NUM_OF_AB {
        num_of_kind += {prizes[i].len() as u32};
    }
    println!("{}", num_of_kind);
}