#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP(i,n,0)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 100000000

typedef long long ll;

vector<int> e[4000];
vector<int> re[4000];
vector<int> vs;
bool used[4000];
int cmp[4000];
int n;

void add_edge(int u, int v) {
    e[u].push_back(v);
    re[v].push_back(u);
}

void dfs(int x) {
    int i;
    used[x] = true;
    rep (i,e[x].size()) if (!used[e[x][i]]) dfs(e[x][i]);
    vs.push_back(x);
}

void rdfs(int x, int d) {
    int i;
    used[x] = true;
    cmp[x] = d;
    rep (i,re[x].size()) if (!used[re[x][i]]) rdfs(re[x][i],d);
}

void scc() {
    int i, d;
    rep (i,2*n) if (!used[i]) dfs(i);
    fill(used,used+2*n,false);
    d = 0;
    rrep (i,2*n-1) if (!used[i]) rdfs(i,d++);
}

int main() {
    int i, j, m;
    int l[2000], r[2000];
    bool ans;
    cin >> n >> m;
    rep (i,n) cin >> l[i] >> r[i];
    rep (i,n) rep (j,i) {
        if (max(l[i],l[j])<=min(r[i],r[j])) {
            add_edge(i,j+n);
            add_edge(j,i+n);
        }
        if (max(l[i],m-1-r[j])<=min(r[i],m-1-l[j])) {
            add_edge(i,j);
            add_edge(j+n,i+n);
        }
        if (max(m-1-r[i],l[j])<=min(m-1-l[i],r[j])) {
            add_edge(i+n,j+n);
            add_edge(j,i);
        }
        if (max(m-1-r[i],m-1-l[j])<=min(m-1-l[i],m-1-l[j])) {
            add_edge(i+n,j);
            add_edge(j+n,i);
        }
    }
    scc();
    ans = true;
    rep (i,n) if (cmp[i] == cmp[i+n]) ans = false;
    if (ans)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    return 0;
}