#include <bits/stdc++.h>   using namespace std;   const int INF = 1000000000;   struct Point {     int x, y;     Point(int x_ = 0, int y_ = 0) : x(x_), y(y_) {}     Point(std::istream &in) {       in >> x >> y;       x *= 2;       y *= 2;     }   };   bool operator<(const Point &a, const Point &b) {     return (a.x < b.x) || (a.x == b.x && a.y < b.y);   }   bool cmp_sum(const Point &a, const Point &b) { return (a.x + a.y < b.x + b.y); }   bool cmp_diff(const Point &a, const Point &b) {     return (a.x - a.y < b.x - b.y);   }   int n, k;   vector<Point> gnome, metro;   vector<int> sorted_x, sorted_y;   vector<int> tree;   int curk;   void upd_val(int x, int val, const vector<int> &coords) {     x = lower_bound(coords.begin(), coords.end(), x) - coords.begin();     x += curk;     tree[x] = min(tree[x], val);     x /= 2;     while (x != 1) {       tree[x] = min(tree[x * 2], tree[x * 2 + 1]);       x /= 2;     }   }   int get_min_val(int l, int r, const vector<int> &coords) {     l = lower_bound(coords.begin(), coords.end(), l) - coords.begin();     r = lower_bound(coords.begin(), coords.end(), r) - coords.begin();     l += curk;     r += curk;     int res = INF;     while (l < r) {       res = min(res, min(tree[l], tree[r]));       l = (l + 1) / 2;       r = (r - 1) / 2;     }     if (l == r) {       res = min(res, tree[l]);     }     return res;   }   void shrink(vector<int> &coord) {     sort(coord.begin(), coord.end());     coord.resize(unique(coord.begin(), coord.end()) - coord.begin());   }   template <typename T>   std::vector<int> argsort(const std::vector<T> &vals, bool reverse = false) {     vector<int> result(vals.size());     for (int i = 0; i < int(vals.size()); ++i) {       result[i] = i;     }     sort(result.begin(), result.end(),          [&](int a, int b) -> bool { return (vals[a] < vals[b]); });     if (reverse) {       std::reverse(result.begin(), result.end());     }     return result;   }   void get_min_dist(const std::vector<Point> &gnome, std::vector<Point> metro,                     std::vector<int> &result) {     sorted_x.clear();     sorted_y.clear();     for (auto &x : gnome) {       sorted_x.push_back(x.x);       sorted_y.push_back(x.y);     }     for (auto &x : metro) {       sorted_x.push_back(x.x);       sorted_y.push_back(x.y);     }     shrink(sorted_x);     shrink(sorted_y);     int nn = gnome.size();     result.assign(nn, INF);     auto indices = argsort(gnome);     sort(metro.begin(), metro.end());     curk = 2;     while (int(sorted_y.size()) > curk) curk *= 2;     {       tree.assign(2 * curk, INF);       int l = 0, r = 0;       while (l < nn) {         int ind = indices[l];         while (r < k && metro[r].x <= gnome[ind].x) {           upd_val(metro[r].y, -metro[r].x - metro[r].y, sorted_y);           ++r;         }         result[ind] = min(result[ind],                           get_min_val(sorted_y.front(), gnome[ind].y, sorted_y) +                               gnome[ind].x + gnome[ind].y);         ++l;       }     }     {       tree.assign(2 * curk, INF);       int l = 0, r = 0;       while (l < nn) {         int ind = indices[l];         while (r < k && metro[r].x <= gnome[ind].x) {           upd_val(metro[r].y, -metro[r].x + metro[r].y, sorted_y);           ++r;         }         result[ind] = min(result[ind],                           get_min_val(gnome[ind].y, sorted_y.back(), sorted_y) +                               gnome[ind].x - gnome[ind].y);         ++l;       }     }     reverse(metro.begin(), metro.end());     reverse(indices.begin(), indices.end());     {       tree.assign(2 * curk, INF);       int l = 0, r = 0;       while (l < nn) {         int ind = indices[l];         while (r < k && metro[r].x >= gnome[ind].x) {           upd_val(metro[r].y, metro[r].x - metro[r].y, sorted_y);           ++r;         }         result[ind] = min(result[ind],                           get_min_val(sorted_y.front(), gnome[ind].y, sorted_y) -                               gnome[ind].x + gnome[ind].y);         ++l;       }     }     {       tree.assign(2 * curk, INF);       int l = 0, r = 0;       while (l < nn) {         int ind = indices[l];         while (r < k && metro[r].x >= gnome[ind].x) {           upd_val(metro[r].y, metro[r].x + metro[r].y, sorted_y);           ++r;         }         result[ind] = min(result[ind],                           get_min_val(gnome[ind].y, sorted_y.back(), sorted_y) -                               gnome[ind].x - gnome[ind].y);         ++l;       }     }   }   int find_dist(pair<pair<int, int>, pair<int, int> > rect, const Point &pnt) {     int sum = pnt.x + pnt.y;     int diff = pnt.x - pnt.y;     int sum_dist =         max(0, -min(rect.first.second, sum) + max(rect.first.first, sum));     int diff_dist =         max(0, -min(rect.second.second, diff) + max(rect.second.first, diff));     return max(sum_dist, diff_dist);   }   void get_all_min_dist(vector<pair<pair<int, int>, pair<int, int> > > rect,                         vector<Point> metro, vector<int> &dist) {     dist.assign(n, INF);     vector<Point> ok_points;     for (int i = 0; i < n; ++i) {       const auto &cr = rect[i];       int a, b, c, d;       tie(a, b) = cr.first;       tie(c, d) = cr.second;       ok_points.emplace_back((a + c) / 2, (a - c) / 2);       ok_points.emplace_back((a + d) / 2, (a - d) / 2);       ok_points.emplace_back((b + c) / 2, (b - c) / 2);       ok_points.emplace_back((b + d) / 2, (b - d) / 2);     }     vector<int> tmp;     get_min_dist(ok_points, metro, tmp);     for (int i = 0; i < n * 4; ++i) {       dist[i / 4] = min(dist[i / 4], tmp[i]);     }     vector<int> sorted_sum;     vector<int> sorted_diff;     for (auto &pnt : rect) {       sorted_sum.push_back(pnt.first.first);       sorted_sum.push_back(pnt.first.second);       sorted_diff.push_back(pnt.second.first);       sorted_diff.push_back(pnt.second.second);     }     for (auto &pnt : metro) {       sorted_sum.push_back(pnt.x + pnt.y);       sorted_diff.push_back(pnt.x - pnt.y);     }     shrink(sorted_sum);     shrink(sorted_diff);     sort(metro.begin(), metro.end(), cmp_sum);     curk = 2;     while (curk < int(sorted_diff.size())) curk *= 2;     vector<pair<pair<int, int>, pair<int, int> > > segment;     for (int i = 0; i < n; ++i) {       segment.emplace_back(make_pair(rect[i].first.first, i), rect[i].second);       if (rect[i].first.first != rect[i].first.second) {         segment.emplace_back(make_pair(rect[i].first.second, i), rect[i].second);       }     }     sort(segment.begin(), segment.end());     {       tree.assign(curk * 2, INF);       int nn = segment.size();       int l = 0, r = 0;       while (l < nn) {         while (r < k && metro[r].x + metro[r].y <= segment[l].first.first) {           upd_val(metro[r].x - metro[r].y, -metro[r].y - metro[r].x, sorted_diff);           ++r;         }         int ind = segment[l].first.second;         dist[ind] =             min(dist[ind], get_min_val(segment[l].second.first,                                        segment[l].second.second, sorted_diff) +                                segment[l].first.first);         ++l;       }     }     reverse(metro.begin(), metro.end());     reverse(segment.begin(), segment.end());     {       tree.assign(curk * 2, INF);       int nn = segment.size();       int l = 0, r = 0;       while (l < nn) {         while (r < k && metro[r].x + metro[r].y >= segment[l].first.first) {           upd_val(metro[r].x - metro[r].y, metro[r].x + metro[r].y, sorted_diff);           ++r;         }         int ind = segment[l].first.second;         dist[ind] =             min(dist[ind], get_min_val(segment[l].second.first,                                        segment[l].second.second, sorted_diff) -                                segment[l].first.first);         ++l;       }     }     sort(metro.begin(), metro.end(), cmp_diff);     segment.clear();     for (int i = 0; i < n; ++i) {       segment.emplace_back(make_pair(rect[i].second.first, i), rect[i].first);       if (rect[i].second.first != rect[i].second.second) {         segment.emplace_back(make_pair(rect[i].second.second, i), rect[i].first);       }     }     sort(segment.begin(), segment.end());     curk = 2;     while (curk < int(sorted_sum.size())) curk *= 2;     {       tree.assign(curk * 2, INF);       int nn = segment.size();       int l = 0, r = 0;       while (l < nn) {         while (r < k && metro[r].x - metro[r].y <= segment[l].first.first) {           upd_val(metro[r].x + metro[r].y, metro[r].y - metro[r].x, sorted_sum);           ++r;         }         int ind = segment[l].first.second;         dist[ind] =             min(dist[ind], get_min_val(segment[l].second.first,                                        segment[l].second.second, sorted_sum) +                                segment[l].first.first);         ++l;       }     }     reverse(metro.begin(), metro.end());     reverse(segment.begin(), segment.end());     {       tree.assign(curk * 2, INF);       int nn = segment.size();       int l = 0, r = 0;       while (l < nn) {         while (r < k && metro[r].x - metro[r].y >= segment[l].first.first) {           upd_val(metro[r].x + metro[r].y, metro[r].x - metro[r].y, sorted_sum);           ++r;         }         int ind = segment[l].first.second;         dist[ind] =             min(dist[ind], get_min_val(segment[l].second.first,                                        segment[l].second.second, sorted_sum) -                                segment[l].first.first);         ++l;       }     }   }   int main() {     ios_base::sync_with_stdio(false);     cin >> n >> k;     for (int i = 0; i < n; ++i) {       gnome.emplace_back(std::cin);     }     for (int i = 0; i < k; ++i) {       metro.emplace_back(std::cin);     }     int min_x = INF, max_x = -INF;     int min_y = INF, max_y = -INF;     for (const auto &pnt : gnome) {       min_x = min(min_x, pnt.x + pnt.y);       max_x = max(max_x, pnt.x + pnt.y);       min_y = min(min_y, pnt.x - pnt.y);       max_y = max(max_y, pnt.x - pnt.y);     }     int result = (max(max_x - min_x, max_y - min_y) + 1) / 2;     if (n > 1 && k) {       vector<int> dist;       get_min_dist(gnome, metro, dist);       auto indices = argsort(dist, true);       vector<pair<pair<int, int>, pair<int, int> > > all_rect;       vector<int> add_dist;       min_x = INF, max_x = -INF;       min_y = INF, max_y = -INF;       for (int i = 0; i < n; ++i) {         const auto &pnt = gnome[indices[i]];         min_x = min(min_x, pnt.x + pnt.y);         max_x = max(max_x, pnt.x + pnt.y);         min_y = min(min_y, pnt.x - pnt.y);         max_y = max(max_y, pnt.x - pnt.y);         int dist = (max(max_x - min_x, max_y - min_y) + 1) / 2;         add_dist.push_back(dist);         all_rect.emplace_back(make_pair(max_x - dist, min_x + dist),                               make_pair(max_y - dist, min_y + dist));       }       result = min(result, dist[indices[0]]);       vector<int> new_dist;       get_all_min_dist(all_rect, metro, new_dist);       for (int i = 0; i < n - 1; ++i) {         int t1 = add_dist[i];         int t2 = new_dist[i];         int t3 = dist[indices[i + 1]];         int x = (max(0, min(2 * t2, t3 + t2 - t1)) + 1) / 2;         result = min(result, max(t1 + x, t3 + t2 - x));       }     }     result = (result + 1) / 2;     cout << result <<   n ;     return 0;   }