Problem:
Score : 200 points

Problem Statement

An X-layered kagami mochi (X ≥ 1) is a pile of X round mochi (rice cake) stacked vertically where each mochi (except the bottom one) has a smaller diameter than that of the mochi directly below it. For example, if you stack three mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, you have a 3-layered kagami mochi; if you put just one mochi, you have a 1-layered kagami mochi.

Lunlun the dachshund has N round mochi, and the diameter of the i-th mochi is d_i centimeters. When we make a kagami mochi using some or all of them, at most how many layers can our kagami mochi have?

Constraints

1 ≤ N ≤ 100

1 ≤ d_i ≤ 100

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
d_1
:
d_N

Output

Print the maximum number of layers in a kagami mochi that can be made.

Sample Input 1

4
10
8
8
6

Sample Output 1

3

If we stack the mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, we have a 3-layered kagami mochi, which is the maximum number of layers.

Sample Input 2

3
15
15
15

Sample Output 2

1

When all the mochi have the same diameter, we can only have a 1-layered kagami mochi.

Sample Input 3

7
50
30
50
100
50
80
30

Sample Output 3

4

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::env;
use std::io::*;
use std::str::*;
use std::mem;
use std::collections::HashMap;

fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let s = stdin.bytes().map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();
    s.parse::<T>().ok().unwrap()
}
fn read_char() -> char {
    let c = read::<String>();
    let c = c.chars().collect::<Vec<char>>();
    c[0]
}
fn read_String_Vec() -> Vec<char> {
    let S = read::<String>();
    S.chars().collect::<Vec<char>>()
}

fn vecchar_to_String(Vs: &Vec<char>) -> String {
    let mut S = String::new();
    for i in 0..Vs.len() {
        S.push(Vs[i]);
    }
    S
}

/*
A : 65
Z : 90
a : 97
z : 122
*/

/*
let N = read::<i32>();
let S = read::<String>();
let S = read_String_Vec();
let C = read_char();
*/

/*
 .to_string() : * -> String
 &*S          : String -> &str
*/

fn main() {
    // main の引数
    /*
        引数なしのときargs.len() = 1;
    */
    let args: Vec<String> = env::args().collect();

    let N = read::<usize>();
    let mut D = Vec::new();
    for n in 0..N {
        let d = read::<i32>();
        D.push(d);
    }
    D.sort();
    let mut diff = 1;
    for i in 1..N {
        if D[i-1] != D[i] {
            diff += 1;
        }
    }
    println!("{}", diff);
}