//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <stack>
#include <queue>
#include <bitset>
#include <numeric>
#include <cassert>
#include <memory>
#include <random>
#include <functional>
#include <complex>
#include <immintrin.h>
#ifdef DEBUG
#include "./CompetitiveProgrammingCpp/debug_VC.hpp"
#include "./CompetitiveProgrammingCpp/Timer.hpp"
#include "./CompetitiveProgrammingCpp/sample.hpp"
#else
#define dump(...)
#endif

/* macro */
#define FOR(i, b, e) for(ll i = (ll)(b); i < (ll)(e); ++i)
#define RFOR(i, b, e) for(ll i = (ll)(e-1); i >= (ll)(b); --i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REPC(x,c) for(const auto& x:(c))
#define REPI2(it,b,e) for(auto it = (b); it != (e); ++it)
#define REPI(it,c) REPI2(it, (c).begin(), (c).end())
#define RREPI(it,c) REPI2(it, (c).rbegin(), (c).rend())
#define REPI_ERACE2(it, b, e) for(auto it = (b); it != (e);)
#define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end())
#define ALL(x) (x).begin(),(x).end()
#define cauto const auto&
/* macro func */
template<class T>
inline auto sort(T& t) { std::sort(ALL(t)); }
template<class T>
inline auto rsort(T& t) { std::sort((t).rbegin(), (t).rend()); }
template<class T>
inline auto unique(T& t) { (t).erase(unique((t).begin(), (t).end()), (t).end()); }
template<class T, class S>
inline auto chmax(T& t, const S& s) { if (s > t) { t = s; return true; } return false; }
template<class T, class S>
inline auto chmin(T& t, const S& s) { if (s < t) { t = s; return true; } return false; }
inline auto BR() { std::cout << "\n"; }

/* type define */
using ll = long long;
using PAIR = std::pair<ll, ll>;
using VS = std::vector<std::string>;
using VL = std::vector<long long>;
using VVL = std::vector<VL>;
using VVVL = std::vector<VVL>;
using VD = std::vector<double>;
template<class T>
using V = std::vector<T>;

/* using std */
using std::cout;
constexpr char endl = '\n';
using std::cin;
using std::pair;
using std::string;
using std::stack;
using std::queue;
using std::vector;
using std::list;
using std::map;
using std::unordered_map;
using std::multimap;
using std::unordered_multimap;
using std::set;
using std::unordered_set;
using std::unordered_multiset;
using std::multiset;
using std::bitset;
using std::priority_queue;

/* Initial processing  */
struct Preprocessing { Preprocessing() { std::cin.tie(0); std::ios::sync_with_stdio(0); }; }_Preprocessing;

/* Remove the source of the bug */
auto pow(signed, signed) { assert(false); return -1; }

/* define hash */
namespace std {
template <>	class hash<std::pair<ll, ll>> { public:	size_t operator()(const std::pair<ll, ll>& x) const { return hash<ll>()(1000000000 * x.first + x.second); } };
}

/* input */
template<class T> std::istream& operator >> (std::istream& is, vector<T>& vec) { for (T& x : vec) is >> x; return is; }

/* constant value */
//constexpr ll MOD = 1000000007;
constexpr ll MOD = 998244353;

//=============================================================================================


class SCC {
	const int m_n;
	const std::unordered_multimap<int, int> m_graph;
	const std::unordered_multimap<int, int> m_revGraph;
	const std::vector<int> m_group;

	auto reverse()const {
		std::unordered_multimap<int, int> graph;
		for (const auto& [f, t] : m_graph) { graph.emplace(t, f); }
		return graph;
	}

	template<class Lambda>
	auto dfs(int n,
		const std::unordered_multimap<int, int>& graph,
		int root,
		std::vector<int>& isUsed,
		const Lambda& lambda) const {
		isUsed[root] = true;
		std::stack<int> q; q.emplace(root);
		while (!q.empty()) {
			auto from = q.top();
			q.pop();

			auto range = graph.equal_range(from);
			for (auto itr = range.first; itr != range.second; ++itr) {
				auto to = itr->second;
				if (!isUsed[to]) {
					q.emplace(to);
					isUsed[to] = true;
					lambda(from, to);
				}
			}
		}
	}

	auto constructGroup()const {
		std::list<int> order;
		{
			std::vector<int> used(m_n);
			for (int from = 0; from < m_n; ++from) if (!used[from]) {
				std::list<int> localOrder;
				localOrder.emplace_front(from);
				dfs(m_n, m_graph, from, used, [&](int f, int t) {
					used[t] = true;
					localOrder.emplace_front(t);
				});
				for (const auto& x : localOrder) {
					order.emplace_front(x);
				}
			}
		}
		std::vector<int> group(m_n);
		{
			std::vector<int> used(m_n);

			int g = 0;
			for (const auto& from : order) if (!used[from]) {
				group[from] = g;
				dfs(m_n, m_revGraph, from, used, [&](int f, int t) {
					used[t] = true;
					group[t] = g;
				});
				++g;
			}
		}
		return group;
	}
public:
	SCC(int n, const std::unordered_multimap<int, int>& graph) :
		m_n(n),
		m_graph(graph),
		m_revGraph(reverse()),
		m_group(constructGroup()) {
	}

	auto isSameGroup(int a, int b)const {
		return m_group[a] == m_group[b];
	}
};

signed main() {
	ll n, m;
	cin >> n >> m;
	V<PAIR> v;
	ll sum = 0;
	v.reserve(2 * n);
	REP(_, n) {
		ll a, b;
		cin >> a >> b;
		v.emplace_back(a, b);
		sum += b - a + 1;
	}
	if (sum > m) {
		cout << "NO" << endl;
		return 0;
	}
	REP(i, n) {
		v.emplace_back(m - v[i].second - 1, m - v[i].first - 1);
	}

	unordered_multimap<int, int> graph;
	REP(i, 2 * n)FOR(j, i + 1, 2 * n) {
		if (v[i].second < v[j].first || v[j].second < v[i].first) { continue; }
		ll ni = (i < n) ? i + n : i - n;
		ll nj = (j < n) ? j + n : j - n;
		graph.emplace(ni, j);
		graph.emplace(nj, i);
	}

	auto scc = SCC(2 * n, graph);
	REP(i, n) if (scc.isSameGroup(i, i + n)) {
		cout << "NO" << endl;
		return 0;
	}
	cout << "YES" << endl;
}