use proconio::input;

fn main() {
    input! {
        n: usize,
        mut io: [(usize, usize); n],
    }

    io.sort_unstable_by_key(|&(_inner, outer)| outer);

    let ans = io
        .windows(2)
        .filter(|window| {
            let prev = window[0];
            let cur = window[1];

            prev.1 > cur.0
        })
        .count();
    println!("{}", ans);
}