#include <bits/stdc++.h>
#define rep(i, a) rep2 (i, 0, a)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) repr2 (i, 0, a)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
using namespace std;
typedef long long ll;

class SCC {
public:
	vector<int> cc;
	SCC(int n) : G(n), H(n), vis(n), cc(n, -1) {}
	void add(int u, int v) {
		G[u].push_back(v);
		H[v].push_back(u);
	}
	void build() {
		rep (i, G.size()) if (!vis[i]) {
			dfs(i);
		}
		int k = 0;
		repr (i, order.size()) if (cc[order[i]] == -1) {
			dfs2(order[i], k++);
		}
	}
private:
	vector<vector<int>> G, H;
	vector<bool> vis;
	vector<int> order;
	void dfs(int curr) {
		vis[curr] = true;
		for (int next : G[curr]) if (!vis[next]) {
			dfs(next);
		}
		order.push_back(curr);
	}
	void dfs2(int curr, int k) {
		cc[curr] = k;
		for (int next : H[curr]) if (cc[next] == -1) {
			dfs2(next, k);
		}
	}
};

int main() {
	int N, M;
	cin >> N >> M;
	SCC scc(N * 2);
	vector<int> L[2], R[2];
	rep (i, 2) {
		L[i].resize(N);
		R[i].resize(N);
	}
	rep (i, N) scanf("%d%d", &L[0][i], &R[0][i]);
	rep (i, N) {
		R[1][i] = M - 1 - L[0][i];
		L[1][i] = M - 1 - R[0][i];
	}
	rep (i, N) rep (j, 2) rep (k, i) rep (l, 2) {
		if (i == k) continue;
		if (L[j][i] <= R[l][k] && R[j][i] >= L[l][k]) {
			scc.add(i + N * j, k + N * !l);
			scc.add(k + N * l, i + N * !j);
		}
	}
	scc.build();
	bool all = true;
	rep (i, N) {
		if (scc.cc[i] == scc.cc[i + N]) {
			all = false;
		}
	}
	if (all) {
		cout << "YES" << endl;
	} else {
		cout << "NO" << endl;
	}
    return 0;
}