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

struct node {
    int x, y;
};
node a[110];
int n, L;

vector<int> X, Y;

int ans;
int main() {
    cin >> n >> L;
    for (int i = 1; i <= n; ++i) cin >> a[i].x >> a[i].y;

    for (int i = 1; i <= n; i++) {
        X.push_back(a[i].x);
        X.push_back(a[i].x - L);
        Y.push_back(a[i].y);
        Y.push_back(a[i].y - L);
    }

    for (int i = 0; i < X.size(); i++) {
        for (int j = 0; j < Y.size(); j++) {
            int cnt = 0;
            int lx = X[i], ly = Y[j];
            for (int k = 1; k <= n; k++)
                if (a[k].x >= lx && a[k].x <= lx + L && a[k].y >= ly && a[k].y <= ly + L)
                    cnt++;

            ans = max(ans, cnt);
        }
    }

    cout << ans << endl;

    return 0;
}