#include <iostream>
#include <vector>
using namespace std;

int main()
{
	int n, m; cin >> n >> m;
	vector<int>blocks(m+1);

	for (int i = 0; i < n; i++) {
		int l, r; cin >> l >> r;
		blocks[l]++;
		blocks[r + 1]--;
		r = m - 1 - r;
		l = m - 1 - l;
		blocks[l]++;
		blocks[r + 1]--;
	}
	for (int i = 0; i < m; i++) {
		if (blocks[i] > 2) {
			cout << "NO" << endl;
			return 0;
		}
		blocks[i+1] += blocks[i];
	}
	cout << "YES" << endl;
    return 0;
}