#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <numeric>
#include <bitset>
#include <complex>
#define rep(x, to) for (int x = 0; x < (to); x++)
#define REP(x, a, to) for (int x = (a); x < (to); x++)
#define foreach(itr, x) for (typeof((x).begin()) itr = (x).begin(); itr != (x).end(); itr++)
#define EPS (1e-14)

using namespace std;

typedef long long ll;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef complex<double> Complex;
typedef vector< vector<int> > Mat;

int N, M;

int imos[4005];

void solve() {
	rep(i, N) {
		int L, R;
		cin >> L >> R;
		L++; R++;
		imos[L] += 1;
		imos[R + 1] += -1;
	}
	rep(i, M) {
		imos[i + 1] += imos[i];
	}
	rep(i, M) {
		if (imos[i + 1] + imos[M - i] >= 3) {
			cout << "NO" << endl;
			return;
		}
	}
	cout << "YES" << endl;
}

int main() {
	cin >> N >> M;
	solve();
	return 0;
}