use std::io::*;
use std::str::FromStr;
use std::collections::HashMap;

#[allow(dead_code)]
fn get_line() -> String {
    let stdin = stdin();
    let mut line = String::new();
    stdin.lock().read_line(&mut line).expect("io error.");
    line.trim().to_string()
}

#[allow(dead_code)]
fn cast<T: FromStr>(s: &str) -> T {
    s.parse().ok().expect("parse error.")
}

#[allow(dead_code)]
fn get_vec<T: FromStr>() -> Vec<T> {
    (&get_line()).split(' ').map(cast::<T>).collect()
}

fn main() {
    get_line();
    let av = get_vec::<u64>();

    let mut cnt = HashMap::<u64, u64>::new();
    for a in av {
        let val = cnt.entry(a).or_insert(0);
        *val += 1;
    }

    let mut ans = 0u64;
    for (_, c) in cnt {
        if c == 1 {ans += 1};
    }
    println!("{}", ans);
}