// includes
#include <bits/stdc++.h>
using namespace std;

// macros
#define pb emplace_back
#define mk make_pair
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define bit(n) (1LL<<(n))
// functions
template <class T>bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;}
template <class T>bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}
template <typename T> ostream &operator<<(ostream &os, const vector<T>& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){os << p.first << " " << p.second; return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
//  types
using ll = long long int;
using P = pair<int, int>;
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
// io
struct fast_io{
  fast_io(){ios_base::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(20);}
} fast_io_;

struct Graph {
  int n = 0;
  vector<int> color;
  vector<vector<int> > edges;
  explicit Graph(int n): n(n) {
    color.resize(n, 0);
    edges.resize(n);
  }
  void adde(int at, int to){
    edges[at].push_back(to);
  }
  bool is_bipartile(){
    for(int i = 0; i < n; i++){
      if(color[i] == 0){
        if(!dfs(i, 1)){
          return false;
        }
      }
    }
    return true;
  }
  bool dfs(int v, int c){
    color[v] = c;
    for(int i: edges[v]){
      if(color[i] == c){
        return false;
      }
      if(color[i] == 0 && !dfs(i, -c))return false;
    }
    return true;
  }
};


int m;
bool cross(int l1, int r1, int l2, int r2){
  if(r1 < l2)return false;
  if(r2 < l1)return false;
  return true;
}

pair<int, int> rev(int l, int r){
  return mk(m - 1 - r, m - 1 - l);
}

int main(int argc, char const* argv[])
{
  int n; cin >> n >> m;
  vector<int> l(n), r(n);
  rep(i, n)cin >> l[i] >> r[i];
  Graph g(n);
  vector<P> V;
  rep(i, n){
    rep(j, n){
      if(i == j)continue;
      if(cross(l[i], r[i], l[j], r[j])){
        int u, v; tie(u, v) = rev(l[j], r[j]);
        if(cross(l[i], r[i], u, v)){
          cout << "NO" << endl;
          return 0;
        }
        g.adde(i, j);
      }else{
        int u, v; tie(u, v) = rev(l[j], r[j]);
        if(cross(l[i], r[i], u, v)){
          V.pb(i, j);
        }
      }
    }
  }
  bool b = g.is_bipartile();
  if(b){
    for(auto p: V){
      if(g.color[p.first] != g.color[p.second])b = false;
    }
  }
  if(b)cout << "YES" << endl;
  else cout << "NO" << endl;
  return 0;
}