#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    int n;
    cin >> n;
    vector<pair<int,int>> xn, xm;
    rep(i,n) {
        int X, Y;
        cin >> X >> Y;
        xn.emplace_back(X+Y, X-Y);
    }
    int m;
    cin >> m;
    rep(i,m) {
        int X, Y;
        cin >> X >> Y;
        xm.emplace_back(X+Y, X-Y);
    }
    sort(xn.begin(),xn.end());
    sort(xm.begin(),xm.end());
    int l = -1;
    int r = 1e7;
    while(r-l>1) {
        int mid = (l+r)/2;
        multiset<int> st;
        int j = 0;
        int k = 0;
        int tmp = 1e9;
        rep(i,n) {
            while(j<m && xm[j].first<=xn[i].first+mid) {
                st.emplace(xm[j].second);
                j++;
            }
            while(k<m && xm[k].first<xn[i].first-mid) {
                st.erase(st.find(xm[k].second));
                k++;
            }
            auto it = st.lower_bound(xn[i].second);
            if(it!=st.end()) {
                tmp = min(tmp, *it - xn[i].second);
            }
            if(it!=st.begin()) {
                it--;
                tmp = min(tmp, xn[i].second-*it);
            }
        }
        if(tmp<=mid) r = mid;
        else l = mid;
    }
    cout << r << endl;
    return 0;
}