//https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

//

struct SAT2 {
    n: usize,
    g: Vec<Vec<usize>>,
    ig: Vec<Vec<usize>>,
}

impl SAT2 {
    fn new(n: usize) -> SAT2 {
        SAT2 {
            n: n,
            g: vec![vec![]; 2 * n],
            ig: vec![vec![]; 2 * n],
        }
    }
    fn add(&mut self, a: usize, b: usize) {
        let g = &mut self.g;
        let ig = &mut self.ig;
        let n = self.n;
        let c = if a >= n {a - n} else {a + n};
        let d = if b >= n {b - n} else {b + n};
        g[c].push(b);
        g[d].push(a);
        ig[b].push(c);
        ig[a].push(d);
    }
    fn dfs_sort(&self, v: usize, used: &mut [bool], q: &mut Vec<usize>) {
        assert!(!used[v]);
        used[v] = true;
        for &u in &self.g[v] {
            if !used[u] {
                self.dfs_sort(u, used, q);
            }
        }
        q.push(v);
    }
    fn solve(&self) -> bool {
        let n = self.n;
        let mut used = vec![false; 2 * n];
        let mut q = Vec::with_capacity(2 * n);
        for i in 0..(2 * n) {
            if used[i] {
                continue;
            }
            self.dfs_sort(i, &mut used, &mut q);
        }
        let mut id = vec![std::u32::MAX; 2 * n];
        let mut k = 0;
        for v in q {
            if id[v] < k {
                continue;
            }
            let mut stack = vec![];
            id[v] = k;
            stack.push(v);
            while let Some(v) = stack.pop() {
                for &u in &self.g[v] {
                    if id[u] > k {
                        id[u] = k;
                        stack.push(u);
                    }
                }
            }
            k += 1;
        }
        for i in 0..n {
            if id[i] == id[i + n] {
                return false;
            }
        }
        true
    }
}

use std::cmp::{max, min};

fn run() {
    input! {
        n: usize,
        m: u32,
        p: [(u32, u32); n],
    }
    let mut sat = SAT2::new(n);
    for i in 0..n {
        let (l, r) = (p[i].0, p[i].1 + 1);
        for &(a, b, x) in [(l, r, i + n), (m - r, m - l, i)].iter() {
            for j in 0..i {
                let (l, r) = (p[j].0, p[j].1 + 1);
                for &(c, d, y) in [(l, r, j + n), (m - r, m - l, j)].iter() {
                    if max(a, c) < min(b, d) {
                        sat.add(x, y);
                    }
                }
            }
        }
    }
    if sat.solve() {
        println!("YES");
    } else {
        println!("NO");
    }
}

fn main() {
    run();
}