#include <bits/stdc++.h>
#include <sys/time.h>
using namespace std;

#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
#define repi(i,a,b) for(long long i = (long long)(a); i < (long long)(b); i++)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define mt make_tuple
#define mp make_pair
#define ZERO(a) memset(a,0,sizeof(a))
template<class T1, class T2> bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
#define exists find_if
#define forall all_of

using ll = long long; using vll = vector<ll>; using vvll = vector<vll>; using P = pair<ll, ll>;
using ld = long double;  using vld = vector<ld>; 
using vi = vector<int>; using vvi = vector<vi>; vll conv(vi& v) { vll r(v.size()); rep(i, v.size()) r[i] = v[i]; return r; }
using Pos = complex<double>;

template <typename T, typename U> ostream &operator<<(ostream &o, const pair<T, U> &v) {  o << "(" << v.first << ", " << v.second << ")"; return o; }
template<size_t...> struct seq{}; template<size_t N, size_t... Is> struct gen_seq : gen_seq<N-1, N-1, Is...>{}; template<size_t... Is> struct gen_seq<0, Is...> : seq<Is...>{};
template<class Ch, class Tr, class Tuple, size_t... Is>
void print_tuple(basic_ostream<Ch,Tr>& os, Tuple const& t, seq<Is...>){ using s = int[]; (void)s{0, (void(os << (Is == 0? "" : ", ") << get<Is>(t)), 0)...}; }
template<class Ch, class Tr, class... Args> 
auto operator<<(basic_ostream<Ch, Tr>& os, tuple<Args...> const& t) -> basic_ostream<Ch, Tr>& { os << "("; print_tuple(os, t, gen_seq<sizeof...(Args)>()); return os << ")"; }
ostream &operator<<(ostream &o, const vvll &v) { rep(i, v.size()) { rep(j, v[i].size()) o << v[i][j] << " "; o << endl; } return o; }
template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '['; rep(i, v.size()) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]";  return o; }
template <typename T>  ostream &operator<<(ostream &o, const set<T> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T, typename U>  ostream &operator<<(ostream &o, const map<T, U> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T, typename U, typename V>  ostream &operator<<(ostream &o, const unordered_map<T, U, V> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it; o << "]";  return o; }
vector<int> range(const int x, const int y) { vector<int> v(y - x + 1); iota(v.begin(), v.end(), x); return v; }
template <typename T> istream& operator>>(istream& i, vector<T>& o) { rep(j, o.size()) i >> o[j]; return i;}
string bits_to_string(ll input, ll n=64) { string s; rep(i, n) s += '0' + !!(input & (1ll << i)); reverse(all(s)); return s; }

template <typename T> unordered_map<T, ll> counter(vector<T> vec){unordered_map<T, ll> ret; for (auto&& x : vec) ret[x]++; return ret;};
string substr(string s, P x) {return s.substr(x.fi, x.se - x.fi); }
struct ci : public iterator<forward_iterator_tag, ll> { ll n; ci(const ll n) : n(n) { } bool operator==(const ci& x) { return n == x.n; } bool operator!=(const ci& x) { return !(*this == x); } ci &operator++() { n++; return *this; } ll operator*() const { return n; } };

size_t random_seed; namespace std { using argument_type = P; template<> struct hash<argument_type> { size_t operator()(argument_type const& x) const { size_t seed = random_seed; seed ^= hash<ll>{}(x.fi); seed ^= (hash<ll>{}(x.se) << 1); return seed; } }; }; // hash for various class
namespace myhash{ const int Bsizes[]={3,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81}; const int xor_nums[]={0x100007d1,0x5ff049c9,0x14560859,0x07087fef,0x3e277d49,0x4dba1f17,0x709c5988,0x05904258,0x1aa71872,0x238819b3,0x7b002bb7,0x1cf91302,0x0012290a,0x1083576b,0x76473e49,0x3d86295b,0x20536814,0x08634f4d,0x115405e8,0x0e6359f2}; const int hash_key=xor_nums[rand()%20]; const int mod_key=xor_nums[rand()%20]; template <typename T> struct myhash{ std::size_t operator()(const T& val) const { return (hash<T>{}(val)%mod_key)^hash_key; } }; };
template <typename T> class uset:public std::unordered_set<T,myhash::myhash<T>> { using SET=std::unordered_set<T,myhash::myhash<T>>; public: uset():SET(){SET::rehash(myhash::Bsizes[rand()%20]);} };
template <typename T,typename U> class umap:public std::unordered_map<T,U,myhash::myhash<T>> { public: using MAP=std::unordered_map<T,U,myhash::myhash<T>>; umap():MAP(){MAP::rehash(myhash::Bsizes[rand()%20]);} };    

struct timeval start; double sec() { struct timeval tv; gettimeofday(&tv, NULL); return (tv.tv_sec - start.tv_sec) + (tv.tv_usec - start.tv_usec) * 1e-6; }
struct init_{init_(){ gettimeofday(&start, NULL); ios::sync_with_stdio(false); cin.tie(0); srand((unsigned int)time(NULL)); random_seed = RAND_MAX / 2 + rand() / 2; }} init__;

static const double EPS = 1e-14;
static const long long mo = 1e9+7;
#define ldout fixed << setprecision(40) 

/***********************/
// 共通部分
/***********************/
#define REP(i,n) for(int i=0;i<(int)n;++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()

typedef long long Weight;
const Weight INF = 1e18;

struct Edge {
    ll src, dst;
    Edge(int src = 0, int dst = 0): 
        src(src), dst(dst){ }
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

// 最大流と最小費用流の有向
// 無向は自分でひっくり返して追加して下さい
void addDirected(Graph& g, ll src, ll dst) {
    g[src].push_back(Edge(src, dst)); 
}

// 強連結分解
// O(V+E)
// const Graph& g               有向グラフ
// vector< vector<ll> >& scc   グラフの強連結成分
void visitStronglyConnectedComponents(const Graph &g, ll v, vector< vector<ll> >& scc,
        stack<ll> &S, vector<bool> &inS,
        vector<ll> &low, vector<ll> &num, ll& time) {
    low[v] = num[v] = ++time;
    S.push(v); inS[v] = true;
    FOR(e, g[v]) {
        ll w = e->dst;
        if (num[w] == 0) {
            visitStronglyConnectedComponents(g, w, scc, S, inS, low, num, time);
            low[v] = min(low[v], low[w]);
        } else if (inS[w])
            low[v] = min(low[v], num[w]);
    }
    if (low[v] == num[v]) {
        scc.push_back(vector<ll>());
        while (1) {
            ll w = S.top(); S.pop(); inS[w] = false;
            scc.back().push_back(w);
            if (v == w) break;
        }
    }
}
void stronglyConnectedComponents(const Graph& g, vector< vector<ll> >& scc) {
    const ll n = g.size();
    vector<ll> num(n), low(n);
    stack<ll> S;
    vector<bool> inS(n);
    ll time = 0;
    rep(u, n) if (num[u] == 0)
        visitStronglyConnectedComponents(g, u, scc, S, inS, low, num, time);
}


#define NOT(a) ((a)+n)
#define flip(i) (tie(l[i], r[i]) = mt(m-r[i]-1, m-l[i]-1))
ll cross(ll l1, ll r1, ll l2, ll r2) {
    if (l1 <= l2 && l2 <= r1) return 1;
    if (l1 <= r2 && r2 <= r1) return 1;
    if (l2 <= l1 && l1 <= r2) return 1;
    if (l2 <= r1 && r1 <= r2) return 1;
    return 0;
}
int main(void) {
    ll n, m; cin >> n >> m;
    vll l(n), r(n);
    rep(i, n) {
        cin >> l[i] >> r[i];
    }
    Graph g(2*n);
    rep(i, n) {
        repi(j, i+1, n) {
            // iがそのままとjがそのままが両立しない
            if (cross(l[i], r[i], l[j], r[j])) {
                addDirected(g, i, NOT(j));
                addDirected(g, j, NOT(i));
            }
            // iが逆とjがそのままが両立しない
            flip(i);
            if (cross(l[i], r[i], l[j], r[j])) {
                addDirected(g, NOT(i), NOT(j));
                addDirected(g, j, i);
            }
            // iが逆とjが逆が両立しない
            flip(j);
            if (cross(l[i], r[i], l[j], r[j])) {
                addDirected(g, NOT(i), j);
                addDirected(g, NOT(j), i);
            }
            // iがそのままとjが逆が両立しない
            flip(i);
            if (cross(l[i], r[i], l[j], r[j])) {
                addDirected(g, i, j);
                addDirected(g, NOT(j), NOT(i));
            }
            flip(j);
        }
    }

    vector<vector<ll>> scc;
    stronglyConnectedComponents(g, scc);

    rep(i, scc.size()) {
        unordered_set<ll> s;
        for (auto x : scc[i]) {
            s.insert(x);
        }
        for (auto x : scc[i]) {
            if (s.count(n + x)) {
                cout << "NO" << endl;
                return 0;
            }
        }
    }
    cout << "YES" << endl;
    return 0;
}