use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: usize = itr.next().unwrap().parse().unwrap();
    let _: usize = itr.next().unwrap().parse().unwrap();
    let mut col: Vec<Vec<usize>> = vec![vec![]; n];
    for _ in 0..n {
        let b = itr.next().unwrap().parse::<usize>().unwrap() - 1;
        let c = itr.next().unwrap().parse::<usize>().unwrap() - 1;
        col[c].push(b);
    }

    let mut ans = 0;
    for i in 0..n {
        col[i].sort();
        let mut j = 0;
        let l = col[i].len();
        let mut tmp = 0;
        while j < l {
            let mut k = 1;
            while j + k < l && col[i][j + k] == col[i][j] {
                k += 1;
            }
            tmp = std::cmp::max(tmp, k);
            j += k;
        }
        ans += l - tmp;
    }
    println!("{}", ans);
}