<?php
$array = explode(" ", trim(fgets(STDIN)));
$N = $array[0];
$M = $array[1];
$L = array();
$R = array();
for($i = 0; $i < $N; $i++) {
  $b = explode(" ", trim(fgets(STDIN)));
  $L[$i] = $b[0];
  $R[$i] = $b[1];
}
$choice = array();
for($i = 0; $i < $N; $i++) {
  $choice[$i] = 0;
}
$last = -1;
$flg = 0;
for($i = 0; $i < $N; $i++) {
  $index = -1;
  $first = $M;
  $temp = 0;
  for($j = 0; $j < $N; $j++) {
    if($choice[$j] == 0) {
      if($last < $L[$j]) {
        if($first > $L[$j]) {
          $first = $L[$j];
          $index = $j;
          $temp = $R[$j];
        } 
      }
      if($last < $M - 1 - $R[$j]) {
        if($first > $M - 1 - $R[$j]) {
          $first = $M - 1 - $R[$j];
          $index = $j;
          $temp = $M - 1 - $L[$j];
        }
      }
    }
  }
  if($index >= 0) {
    $last = $temp;
    $flg++;
    $choice[$index] = 1;
  } else {
    break;
  }
}
$ans = 'YES';
if($flg < $N) $ans = 'NO';
print($ans);
print("\n");
?>