//https://ncode.syosetu.com/n4830bu/274/
#include <bits/stdc++.h>
using namespace std;

int main() {
    int N, M;
    cin >> N >> M;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> que;
    for (int i = 0; i < N; i++) {
        int l, r;
        cin >> l >> r;
        if (l - 1 > M - 1 - r) {
            l = M - 1 - l;
            r = M - 1 - r;
            swap(l, r);
        }
        r++;
        que.push({l, r});
    }
    int maine = 0;
    while (!que.empty()) {
        auto [l, r] = que.top();
        que.pop();
        if (maine <= l) {
            maine = r;
            continue;
        }
        r--;
        l = M - 1 - l;
        r = M - 1 - r;
        swap(l, r);
        r++;
        if (maine <= l)
            que.push({l, r});
        else {
            cout << "NO" << endl;
            return 0;
        }
    }
    cout << "YES" << endl;
    return 0;
}