#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

int main()
{
    int n, m;
    cin >> n >> m;

    vector<int> l(n), r(n);
    for(int i=0; i<n; ++i)
        cin >> l[i] >> r[i];

    int x = 0;
    vector<bool> used(n, false);
    for(int i=0; i<n; ++i){
        int k = -1;
        int l2 = INT_MAX;
        int r2 = INT_MAX;
        for(int j=0; j<n; ++j){
            if(used[j])
                continue;
            if(x <= l[j] && l[j] < l2){
                k = j;
                l2 = l[j];
                r2 = r[j];
            }
            if(x <= (m - 1 - r[j]) && (m - 1 - r[j]) < l2){
                k = j;
                l2 = m - 1 - r[j];
                r2 = m - 1 - l[j];
            }
        }

        if(k == -1){
            cout << "NO" << endl;
            return 0;
        }
        used[k] = true;
        x = r2 + 1;
    }

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