#include <iostream>

#include <array>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>

#include <string>
#include <sstream>

#include <memory>
#include <cassert>

#include <functional>

using namespace std;

const int MOD = 1000000007;

typedef unsigned long long ull;

int main()
{
	int N, M;
	cin >> N >> M;
	//vector<pair<int, int>> data(N);
	unordered_map<int, int> m;
	for (int i = 0; i < N; ++i) {
		int a, b;
		cin >> a >> b;
		//data[i] = pair<int, int>(a, b);

		for (int j = a; j <= b; ++j) {
			++m[j];
		}
	}

	for (auto p : m) {
		if (p.second >= 3) {
			cout << "NO" << endl;
			return 0;
		}
		if (p.second == 2) {
			if (m[M - 1 - p.first] >= 1) {
				cout << "NO" << endl;
				return 0;
			}
		}
	}

	cout << "YES" << endl;
	return 0;
}