#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n,m;
    cin>>m>>n;
    int l[2*m],r[2*m];
    for(int ctr1=0; ctr1<m; ctr1++)
    {
        cin>>l[ctr1]>>r[ctr1];
        l[m+ctr1]=n-r[ctr1]-1;
        r[m+ctr1]=n-l[ctr1]-1;
    }
    unordered_set<int> hs;
    vector<int> rez;
    rez.push_back(0);
    hs.insert(0);
        for(int ctr2=0; ctr2<rez.size(); ctr2++)
        {
            for(int ctr3=0; ctr3<m; ctr3++)
            {
                if(!hs.count(ctr3) && !hs.count(ctr3+m))
                {
                    bool b1=(l[rez[ctr2]]<=r[ctr3] && l[ctr3] <= r[rez[ctr2]]),b2=(l[rez[ctr2]]<=r[m+ctr3] && l[m+ctr3] <= r[rez[ctr2]]);
                    if(b1==b2)
                    {
                        if(!b1)
                            continue;
                        else
                        {
                            cout<<"NO"<<endl;
                            return 0;
                        }
                    }
                    else
                    {
                        if(b2)
                        {
                            rez.push_back(ctr3);
                            hs.insert(ctr3);
                        }
                        else
                        {
                            rez.push_back(m+ctr3);
                            hs.insert(m+ctr3);
                        }
                    }
                }
            }
            if(ctr2==rez.size()-1)
            {
                for(int ctr3=0; ctr3<m; ctr3++)
                {
                    if(hs.count(ctr3) || hs.count(ctr3+m))
                        continue;
                    rez.push_back(ctr3);
                    hs.insert(ctr3);
                    break;
                }
            }
        }
    for(int ctr1=0; ctr1<rez.size(); ctr1++)
        for(int ctr2=ctr1+1; ctr2<rez.size(); ctr2++)
            if (l[rez[ctr1]]<=r[rez[ctr2]] && l[rez[ctr2]] <= r[rez[ctr1]])
            {
                cout<<"NO"<<endl;

                return 0;
            }
    cout<<"YES"<<endl;
    return 0;
}