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

using S = int;
using F = int;

S e(){
    return 0;
}

S op(S l, S r){
    return max(l, r);
}

S mapping(F l, S r){
    return l + r;
}

F composition(F l, F r){
    return l + r;
}

F id(){
    return 0;
}

void solve(){
    int n, m;
    cin >> n >> m;
    lazy_segtree<S, op, e, F, mapping, composition, id> seg(m);
    vector<pair<int, int>> lr(n);
    int l, r, ll, rr;
    for(int i = 0; i < n; i++){
        cin >> l >> r;
        if(l > r) swap(l, r);
        ll = m - 1 - r;
        rr = m - 1 - l;
        if(r <= rr) lr[i] = {l, r};
        else lr[i] = {ll, rr};
    }
    sort(lr.begin(), lr.end());
    for(auto tmp:lr){
        l = tmp.first;
        r = tmp.second;
        int ma = seg.prod(l, r + 1);
        if(ma == 0){
            seg.apply(l, r + 1, 1);
            continue;
        }
        ll = m - 1 - r;
        rr = m - 1 - l;
        ma = seg.prod(ll, rr + 1);
        if(ma == 0){
            seg.apply(ll, rr + 1, 1);
        }
        else{
            cout << "NO\n";
            return;
        }
    }
    cout << "YES\n";
}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    int t;
    t = 1;
    //cin >> t;
    while(t--) solve();
}