func_code_string: #include <bits/stdc++.h>   using namespace std;   long long inf = 4e18, mod = 1e9 + 7;   vector<pair<pair<long long, long long>, pair<long long, long long>>> v;   int segt[4 * 6000000 + 5], lazy[4 * 6000000 + 5];   void push(int v, int l, int r) {     segt[v] += lazy[v];     if (l != r) {       lazy[2 * v] += lazy[v];       lazy[2 * v + 1] += lazy[v];     }     lazy[v] = 0;   }   void update_range(int v, int l, int r, int qs, int qe, int x) {     push(v, l, r);     if (l > qe || r < qs) return;     if (qs <= l && r <= qe) {       lazy[v] += x;       push(v, l, r);       return;     }     int m = (l + r) / 2;     update_range(2 * v, l, m, qs, qe, x);     update_range(2 * v + 1, m + 1, r, qs, qe, x);     segt[v] = max(segt[2 * v], segt[2 * v + 1]);   }   int query(int v, int l, int r, int qs, int qe) {     push(v, l, r);     if (l > qe || r < qs) return 0;     if (qs <= l && r <= qe) return segt[v];     int m = (l + r) / 2;     int val1 = query(2 * v, l, m, qs, qe);     int val2 = query(2 * v + 1, m + 1, r, qs, qe);     return max(val1, val2);   }   void solve() {     int n, r;     cin >> n >> r;     for (int i = 1; i <= n; i++) {       int x, y;       cin >> x >> y;       int X = x + y, Y = y - x;       int lx, ly, ux, uy;       lx = X - r, ux = X + r, ly = Y - r, uy = Y + r;       lx += 3000000;       ux += 3000000;       ly += 3000000;       uy += 3000000;       v.push_back({{ly, 0}, {lx, ux}});       v.push_back({{uy, 1}, {lx, ux}});     }     sort(v.begin(), v.end());     int res = 0;     for (auto it : v) {       if (it.first.second == 0)         update_range(1, 0, 6000000, it.second.first, it.second.second, 1);       else         update_range(1, 0, 6000000, it.second.first, it.second.second, -1);       int val = query(1, 0, 6000000, 0, 6000000);       res = max(res, val);     }     cout << res << endl;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t = 1;     while (t--) solve();   }   