#include "bits/stdc++.h"
using namespace std;

#define REP(i, n) for(int i=0; i<(n); i++)

int N,M;
struct L{
    int l, r; bool rev, fix;
    L(){
        rev = false;
        fix = false;
    }
    int le() {
        return (rev ? M - 1 - l : l);
    }
    int ri() {
        return (rev ? M - 1 - r : r);
    }
};
signed main()
{
    cin >> N >> M;
    vector<L> Ls(N);
    REP(i,N) {
        cin >> Ls[i].l >> Ls[i].r;
    }
    int k = 0;
    bool ok = true;
    while(k <= M/2) {
        vector<int> hasi;
        vector<int> hasr;
        REP(i,N) {
            L l = Ls[i];
            if (l.le() <= k && k <= l.ri()) hasi.push_back(i);
            if (M-1-l.ri() <= k && k <= M-1-l.le()) hasr.push_back(i);
        }
        // 真ん中は別処理
        if (M%2==1 && k==M/2) {
            if (hasi.size() >= 2) {
                ok = false;
                break;
            }
        } else if (hasi.size() + hasr.size() >= 3) {
            ok = false;
            break;
        }
        if (hasi.size() == 2) {
            bool hasrev = false;
            for (auto&& j : hasi) {
                if (Ls[j].fix == false && Ls[j].rev == false) {
                    Ls[j].rev = true;
                    hasrev = true;
                }
                Ls[j].fix = true;
            }
            if (!hasrev) ok = false;
        } else if (hasr.size() == 2) {
            bool hasrev = false;
            for (auto&& j : hasr) {
                if (Ls[j].fix == false && Ls[j].rev == false) {
                    Ls[j].rev = true;
                    hasrev = true;
                }
                Ls[j].fix = true;
            }
            if (!hasrev) ok = false;
        }
        if (hasi.size() + hasr.size() == 2) {
            for (auto&& j : hasi) {
                Ls[j].fix = true;
            }
            for (auto&& j : hasr) {
                Ls[j].fix = true;
            }
        }
        if (!ok) break;
        k++;
    }
    cout << (ok ? "YES" : "NO") << endl;
    return 0;
}