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

void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    int n;
    cin >> n;
    vector<pair<int, int>> s(n);
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        s[i] = {x + y, x - y};
    }
    int m;
    cin >> m;
    vector<pair<int, int>> t(m);
    for (int i = 0; i < m; i++) {
        int x, y;
        cin >> x >> y;
        t[i] = {x + y, x - y};
    }
    sort(t.begin(), t.end());
    int ng = -1, ok = 1e6;
    while (ng + 1 < ok) {
        int mid = (ng + ok) / 2;
        multiset<int> st;
        bool is_ok = false;
        int l = 0, r = 0;
        for (auto [u, v] : s) {
            while (r < m && t[r].first <= u + mid) {
                st.insert(t[r].second);
                r++;
            }
            while (l < r && t[l].first < u - mid) {
                st.erase(st.find(t[l].second));
                l++;
            }
            // cout << l << " " << r << endl;
            auto it = st.lower_bound(v);
            if (it != st.end() && *it <= v + mid) {
                is_ok = true;
                break;
            }
            if (it != st.begin() && *prev(it) >= v - mid) {
                is_ok = true;
                break;
            }
        }

        if (is_ok) {
            ok = mid;
        } else {
            ng = mid;
        }
    }
    cout << ok << endl;
}