#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 op(int a, int b) {
    return a+b;
}

int e() {
    return 0;
}

int main()
{
    int n;
    cin >> n;
    vector<pair<int,int>> xn, xm;
    const int base = 1e3;
    rep(i,n) {
        int X, Y;
        cin >> X >> Y;
        xn.emplace_back(X+Y, X-Y+base);
    }
    int m;
    cin >> m;
    rep(i,m) {
        int X, Y;
        cin >> X >> Y;
        xm.emplace_back(X+Y, X-Y+base);
    }
    sort(xn.begin(),xn.end());
    sort(xm.begin(),xm.end());
    int l = -1;
    int r = 1e7;
    while(r-l>1) {
        fenwick_tree<int> bit(2*base+5);
        int mid = (l+r)/2;
        int j = 0;
        int k = 0;
        bool ok = false;
        rep(i,n) {
            while(j<m && xm[j].first<=xn[i].first+mid) {
                bit.add(xm[j].second,1);
                j++;
            }
            while(k<m && xm[k].first<xn[i].first-mid) {
                bit.add(xm[k].second, -1);
                k++;
            }
            int val = bit.sum(max(0, xn[i].second-mid), min(2*base+5, xn[i].second+mid+1));
            if(val>=1) {
                ok = true;
                break;
            }
        }
        if(ok) r = mid;
        else l = mid;
    }
    cout << r << endl;
    return 0;
}