#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;

int main(){
    int n,m;
    cin>>n>>m;
    atcoder::two_sat ts(m);
    vector<array<int,2>> a(n);
    for(int i=0;i<n;i++){
        cin>>a[i][0]>>a[i][1];
        for(int j=0;j<i;j++){
            if(max(a[i][0],a[j][0])<=min(a[i][1],a[j][1])){
                ts.add_clause(i,1,j,1);
                ts.add_clause(i,0,j,0);
            }
            if(max(m-1-a[i][1],a[j][0])<=min(m-1-a[i][0],a[j][1])){
                ts.add_clause(i,1,j,0);
                ts.add_clause(i,0,j,1);
            }
        }
    }
    cout<<(ts.satisfiable()?"YES":"NO")<<endl;
}