#include <bits/stdc++.h>

typedef long long ll;
typedef unsigned long long ull;

#define FOR(i,a,b) for(int (i)=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define RANGE(vec) (vec).begin(),(vec).end()

using namespace std;
class SCC {
public:
    // for input or output data
    std::vector<std::vector<int>> G_;
    std::vector<int> cmp_;

    // for algorithm
    std::vector<std::vector<int>> rG_;
    std::vector<int> vs_;
    std::vector<bool> used_;

    SCC() {}
    SCC(int V) { init(V); }
    void init(int V) {
        G_.resize(V);
        rG_.resize(V);
        used_.resize(V);
        cmp_.resize(V);
    }
    ~SCC() {}
    void add(int from, int to) {
        assert(0 <= from && from <  (int)G_.size());
        assert(0 <= to && to <  (int)rG_.size());
        G_[from].push_back(to);
        rG_[to].push_back(from);
    }
    void dfs(int v) {
        used_[v] = true;
        for (int i = 0; i < (int)G_[v].size(); ++i)
        {
            if (!used_[G_[v][i]])
                dfs(G_[v][i]);
        }
        vs_.push_back(v);
    }
    void rdfs(int v, int k) {
        used_[v] = true;
        cmp_[v] = k;
        for (int i = 0; i < (int)rG_[v].size(); ++i)
        {
            if (!used_[rG_[v][i]])
                rdfs(rG_[v][i], k);
        }
    }
    //
    // O(|V|+|E|)
    //
    int decompose() {
        int V = G_.size();
        std::fill(used_.begin(), used_.end(), false);
        vs_.clear();
        for (int v = 0; v < V; ++v)
            if (!used_[v])
                dfs(v);
        std::fill(used_.begin(), used_.end(), false);
        int k = 0;
        for (int i = vs_.size()-1; i >= 0; i--)
            if (!used_[vs_[i]])
                rdfs(vs_[i], k++);
        return k;
    }
    const std::vector<int> &components() const {
        return cmp_;
    }
};
class TwoSAT : public SCC {
public:
    int n_;
    vector<bool> logic_;
    int True(int x) { return x; }
    int Fals(int x) { return (x+n_)%(2*n_); }

    TwoSAT(int nVar) { init(nVar); }
    void init(int nVar) {
        logic_.resize(nVar, false);
        n_ = nVar;
        SCC::init(nVar*2);
    }
    void add(int x1, int x2) {
        SCC::add(True(x1), True(x2));
        SCC::add(Fals(x2), Fals(x1)); // add contraposition edge
    }
    void setTrue(int x) {
        SCC::add(Fals(x), True(x));
    }
    void setFalse(int x) {
        SCC::add(True(x), Fals(x));
    }
    bool solve() {
        SCC::decompose();
        for (int i = 0; i < n_; i++)
        {
            int a = SCC::cmp_[True(i)];
            int b = SCC::cmp_[Fals(i)];
            if (a == b)
                return false;
            logic_[i] = (a > b);
        }
        return true;
    }
};

bool rangeIsCross(int s1, int e1, int s2, int e2)
{
    return max(s1,s2) <= min(e1,e2);
}

class TheWall
{
public:
    bool rangeIsCross(const pair<int,int> &a,
                      const pair<int,int> &b)
    {
        return ::rangeIsCross(a.first, a.second, b.first, b.second);
    }
    void solve(void)
    {
        int N,M;
        cin>>N>>M;
        vector<pair<int,int>> blks;
        REP(i,N)
        {
            int l,r;
            cin>>l>>r;
            blks.emplace_back(l,r);
        }
        TwoSAT sat(N);

#define T(x) sat.True(x)
#define F(x) sat.Fals(x)

        // block 反転(first,second が逆になる)
#define flip(BLK) make_pair(M-1-(BLK).second, M-1-(BLK).first)

        REP(i,N)
        {
            REP(j,i)
            {
                // 交差しないときに辺を張るのではなくて、
                // 交差するときにそれを回避するための制約として辺を張る
                if (rangeIsCross(blks[i], blks[j]))
                    sat.add(T(i),F(j));
                if (rangeIsCross(blks[i],flip(blks[j])))
                    sat.add(T(i),T(j));
                if (rangeIsCross(flip(blks[i]),blks[j]))
                    sat.add(F(i),F(j));
                if (rangeIsCross(flip(blks[i]),flip(blks[j])))
                    sat.add(F(i),T(j));
            }
        }
        if ( sat.solve() )
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
};

#if 1
int main(int argc, char *argv[])
{
        ios::sync_with_stdio(false);
        auto obj = new TheWall();
        obj->solve();
        delete obj;
        return 0;
}
#endif