#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (Y);++(X))
#define rrep(X,Y) for (int (X) = (Y)-1;(X) >=0;--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()
#define eb emplace_back
#define UNIQUE(X) (X).erase(unique(all(X)),(X).end())

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<class T> using vv=vector<vector<T>>;
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"{"; rep(i,t.size()) {os<<t[i]<<",";} os<<"}"<<endl; return os;}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
const ll MOD=1e9+7;

int dfs(vv<int> &g,vector<int> &c,int v,int t){
  //cout<<c<<v<<","<<t<<endl;
  if(c[v]) return c[v]!=t;
  c[v]=t;
  int re=0;
  for(const int &w:g[v])
    re|=dfs(g,c,w,3-t);
  //cout<<re<<endl;
  return re;
}

int inter(pii a,pii b){//cout<<a<<b<<endl;
  if(a.Y<b.X) return 0;
  if(b.Y<a.X) return 0;
  return 1;
}

int main(){
  ios_base::sync_with_stdio(false);
  cout<<fixed<<setprecision(0);
  int n,m;
  cin>>n>>m;
  vector<pii> a(n);
  rep(i,n) cin>>a[i].X>>a[i].Y;
  vv<int> g(n);
  rep(i,n)rep(j,i){
    pii tmp; tmp.X=m-1-a[j].Y; tmp.Y=m-1-a[j].X;
    //cout<<a[i]<<a[j]<<tmp<<endl;
    if(inter(a[i],a[j]) || inter(a[i],tmp)){
      g[i].pb(j); g[j].pb(i);
    }
  }
  //cout<<g;
  vector<int> c(n);
  int f=0;
  rep(i,n)if(!c[i]){
    f|=dfs(g,c,i,2);
    //cout<<c;
  }
  cout<<(!f?"YES":"NO")<<endl;
  return 0;
}