#include<bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 1e9 + 7;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;


template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in : v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e : t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

template< typename T = int >
struct Edge {
  int from, to;
  T cost;
  int idx;

  Edge() = default;

  Edge(int from, int to, T cost = 1, int idx = -1) : from(from), to(to), cost(cost), idx(idx) {}

  operator int() const { return to; }
};

template< typename T = int >
struct Graph {
  vector< vector< Edge< T > > > g;
  int es;

  Graph() = default;

  explicit Graph(int n) : g(n), es(0) {}

  size_t size() const {
    return g.size();
  }

  void add_directed_edge(int from, int to, T cost = 1) {
    g[from].emplace_back(from, to, cost, es++);
  }

  void add_edge(int from, int to, T cost = 1) {
    g[from].emplace_back(from, to, cost, es);
    g[to].emplace_back(to, from, cost, es++);
  }

  void read(int M, int padding = -1, bool weighted = false, bool directed = false) {
    for(int i = 0; i < M; i++) {
      int a, b;
      cin >> a >> b;
      a += padding;
      b += padding;
      T c = T(1);
      if(weighted) cin >> c;
      if(directed) add_directed_edge(a, b, c);
      else add_edge(a, b, c);
    }
  }
};

template< typename T = int >
using Edges = vector< Edge< T > >;


/**
 * @brief Manhattan-Minimum-Spanning-Tree
 */
template< typename T >
Edges< T > manhattan_minimum_spanning_tree(vector< T > xs, vector< T > ys) {
  assert(xs.size() == ys.size());
  Edges< T > ret;
  int n = (int) xs.size();

  vector< int > ord(n);
  iota(ord.begin(), ord.end(), 0);

  for(int s = 0; s < 2; s++) {
    for(int t = 0; t < 2; t++) {
      auto cmp = [&](int i, int j) -> bool {
        return xs[i] + ys[i] < xs[j] + ys[j];
      };
      sort(ord.begin(), ord.end(), cmp);

      map< T, int > idx;
      for(int i:ord) {
        for(auto it = idx.lower_bound(-ys[i]);
            it != idx.end(); it = idx.erase(it)) {
          int j = it->second;
          if(xs[i] - xs[j] < ys[i] - ys[j]) break;
          ret.emplace_back(i, j, abs(xs[i] - xs[j]) + abs(ys[i] - ys[j]));
        }
        idx[-ys[i]] = i;
      }
      swap(xs, ys);
    }
    for(int i = 0; i < n; i++) xs[i] *= -1;
  }
  return ret;
}

void solve(){
    int n; cin >> n;
    vector<int> x, y;
    for(int i=0; i<n; i++){
        int a, b; cin >> a >> b;
        x.push_back(a);
        y.push_back(b);
    }
    int m; cin >> m;
    for(int i=0; i<m; i++){
        int a, b; cin >> a >> b;
        x.push_back(a);
        y.push_back(b);
    }

    auto es = manhattan_minimum_spanning_tree(x, y);
    int ans = 1e9;
    for(auto e : es){
        if(e.from<n&&e.to>=n || e.from>=n&&e.to<n) ans = min(ans, e.cost);
    }

    cout << ans << '\n';
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    int T=1;
    //cin >> T;
    while(T--) solve();
}