fn main() {
    let mut xx = String::new();
    std::io::Read::read_to_string(&mut std::io::stdin(), &mut xx).ok();
    let xx: Vec<usize> = xx.split_whitespace().flat_map(str::parse).collect();

    let mut count = vec![0; xx[0] + 1];
    for &n in &xx[1..] {
        count[n] += 1;
    }

    let answer = count.iter().filter(|&&n| n == 1).count() - 2;

    println!("{answer}");
}