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

typedef long long ll;
typedef vector< int > vi;
typedef vector< vi > vvi;
typedef vector< ll > vl;
typedef vector< vl > vvl;
typedef pair< int, int > pii;
typedef vector< pii > vp;
typedef vector< double > vd;
typedef vector< vd > vvd;
typedef vector< string > vs;

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

template< class T1, class T2 >
int upmax( T1 &x, T2 v ){
  if( x < v ){
    x = v;
    return 1;
  }
  return 0;
}

const int INF = 0x3f3f3f3f;

int N, M;
vp L_R;

void init(){
  cin >> N >> M;
  L_R = vp( N );
  for( int i = 0; i < N; ++i )
    cin >> L_R[ i ].first >> L_R[ i ].second;
}

void preprocess(){
  
}

void solve(){
  vi vis( N );
  int rb = 0; // rb )
  for( int i = 0; i < N; ++i ){
    int min_lb = INF, min_id = -1;
    for( int j = 0; j < N; ++j ){
      if( vis[ j ] ) continue;
      if( M - 1 - L_R[ j ].second < L_R[ j ].first )
        L_R[ j ].first = M - 1 - L_R[ j ].first,
        L_R[ j ].second = M - 1 - L_R[ j ].second,
        swap( L_R[ j ].first, L_R[ j ].second );
      if( L_R[ j ].first < rb ){
        L_R[ j ].first = M - 1 - L_R[ j ].first,
        L_R[ j ].second = M - 1 - L_R[ j ].second;
        if( not ( L_R[ j ].first <= L_R[ j ].second ) )
          swap( L_R[ j ].first, L_R[ j ].second );
      }
      if( rb <= L_R[ j ].first )
        if( upmin( min_lb, L_R[ j ].first ) )
          min_id = j;
    }
    if( min_id == -1 )
      cout << "NO" << endl, exit( 0 );
    // cout << min_id << endl;
    vis[ min_id ] = 1;
    rb = L_R[ min_id ].second + 1;
  }
  cout << "YES" << endl;
}

signed main(){
  ios::sync_with_stdio( 0 );
  init();
  preprocess();
  solve();
  return 0;
}