// Uloha: KSP-31-3-2
// Napsal Marek podle Zuzcina reseni.
// C++17

#include <iostream>
#include <vector>
#include <algorithm>
#include <tuple>
#include <queue>
#include <cmath>

using namespace std;

int solve_nn(vector<pair<double, double>> points, double k) {
    auto by_y_coord = [](auto p1, auto p2) { return p1.second < p2.second; };
    sort(points.begin(), points.end(), by_y_coord);
    int result = 0;
    for (auto [a, b] : points) {
        queue<double> lifo;
        for (auto [x, y] : points) {
            if (a <= x && x <= a+k && b-k <= y && y <= b+k) {
                lifo.push(y);
                while (y - lifo.back() > k) lifo.pop();
                result = max<int>(result, lifo.size());
            }
        }
    }
    return result;
}


auto read_input() {
    int n; cin >> n;
    double k; cin >> k;
    auto points = vector<pair<double, double>>(n);
    for (auto&& [x, y] : points) cin >> x >> y;
    return make_tuple(points, k);
}

int main() {
    cout << apply(solve_nn, read_input()) << endl; 
    return 0; 
}