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: Accepted)

use input::Input;
use std::collections::HashSet;

fn main() {
    let mut input = Input::new();

    let n: usize = input.parse();
    let mut st = HashSet::new();
    for _ in 0..n {
        st.insert(input.parse::<String>());
    }
    println!("{}", st.len());
}

#[allow(dead_code)]
mod input {
    use std::io::{stdin, BufRead, StdinLock};

    pub struct Input<'a> {
        memory: Vec<String>,
        reader: StdinLock<'a>,
    }

    impl<'a> Input<'a> {
        pub fn new() -> Self {
            Self {
                memory: Vec::new(),
                reader: Box::leak(Box::new(stdin())).lock(),
            }
        }
        pub fn read_line(&mut self) -> String {
            let mut s = String::new();
            self.reader.read_line(&mut s).expect("read_line failed.");
            s
        }
        pub fn parse<T: std::str::FromStr>(&mut self) -> T {
            if self.memory.len() == 0 {
                let s = self.read_line();
                self.memory = s.split_whitespace().map(String::from).rev().collect();
            }
            self.memory.pop().unwrap().parse().ok().unwrap()
        }
    }
}