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

struct scc{
	int n;
	vector<vector<int>> edge, rev, parse;
	vector<int> vs, cmp;
	vector<bool> used;

	scc(int n_){
		n = n_;
		edge.assign(n, vector<int>());
		rev.assign(n, vector<int>());
		cmp.assign(n, 0);
		used.assign(n, false);
	}

	void addedge(int from, int to){
		edge[from].emplace_back(to);
		rev[to].emplace_back(from);
	}

	void dfs(int v){
		used[v] = true;
		for(auto&& e:edge[v]) if(!used[e]) dfs(e);
		vs.emplace_back(v);
	}

	void rdfs(int v, int k){
		used[v] = true;
		cmp[v] = k;
		for(auto&& e:rev[v]) if(!used[e]) rdfs(e, k);
		parse[k].emplace_back(v);
	}

	int calc(){
		for(int i = 0; i < n; i++) if(!used[i]) dfs(i);
		fill(used.begin(), used.end(), false);
		int k = 0;
		for(int i = vs.size() - 1; i >= 0; i--){
			int v = vs[i];
			if(!used[v]){
				parse.emplace_back(vector<int>());
				rdfs(v, k++);
			}
		}
		return k;
	}

	bool same(int a, int b){
		return cmp[a] == cmp[b];
	}
};

int rev(int p, int m){
	return m - p - 1;
}

int main(){
	scc s(6000);
	int n, m;
	cin >> n >> m;
	int l[n], r[n];
	for(int i = 0; i < n; i++) cin >> l[i] >> r[i];
	for(int i = 0; i < n; i++) for(int j = i + 1; j < n; j++){
		if(l[i] <= r[j] && l[j] <= r[i]){
			s.addedge(j, 3000 + i);
			s.addedge(i, 3000 + j);
		}
		if(rev(r[i], m) <= r[j] && l[j] <= rev(l[i], m)){
			s.addedge(j, i);
			s.addedge(3000 + i, 3000 + j);
		}
		if(l[i] <= rev(l[j], m) && rev(r[j], m) <= r[i]){
			s.addedge(3000 + j, 3000 + i);
			s.addedge(i, j);
		}
		if(rev(r[i], m) <= rev(l[j], m) && rev(r[j], m) <= rev(l[i], m)){
			s.addedge(3000 + i, j);
			s.addedge(3000 + j, i);
		}
	}
	s.calc();
	for(int i = 0; i < n; i++) if(s.same(i, 3000 + i)){
		cout << "NO" << endl;
		return 0;
	}
	cout << "YES" << endl;
}