#include <bits/stdc++.h>
#include <cstdint>
#include <sys/time.h>

typedef std::int_fast32_t  s32;
typedef std::uint_fast32_t u32;
typedef std::int_fast64_t  s64;
typedef std::uint_fast64_t u64;

const unsigned long mod = 1000000007;

int N, M;
int C[4096];

bool solve() {
  for(int i = 0; i < M; ++i) {
    if( C[i] + C[M - i - 1] >= 3 ) {
      return false;
    }
  }
  return true;
}

int main() {

  std::cin >> N >> M;
  for(int i = 0; i < N; ++i) {
    int L, R;
    std::cin >> L >> R;
    for(int j = L; j <= R; ++j) {
      C[j] += 1;
    }
  }

  std::cout << (solve() ? "YES" : "NO") << std::endl;
    
  return 0;
}