#include <bits/stdc++.h>

using namespace std;

#define int long long

const int N = 2e5 + 5, M = 1e3 + 5;

int n, x[N], y[N], m, ans = 1e18, l[M][M], r[M][M];

vector<int> v[N];

signed main() {
  for (int i = 0; i <= 1000; i++) {
    v[i].push_back(-1e18);
    v[i].push_back(1e18);
  }
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> x[i] >> y[i];
  }
  cin >> m;
  for (int i = 1, _x, _y; i <= m; i++) {
    cin >> _x >> _y;
    v[_x].push_back(_y);
  }
  for (int i = 0; i <= 1000; i++) {
    sort(v[i].begin(), v[i].end());
    for (int j = 0; j <= 1000; j++) {
      auto tmp = upper_bound(v[i].begin(), v[i].end(), j) - v[i].begin() - 1;
      l[i][j] = v[i][tmp];
      tmp = lower_bound(v[i].begin(), v[i].end(), j) - v[i].begin();
      r[i][j] = v[i][tmp];
    }
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 0; j <= 1000; j++) {
      ans = min(ans, abs(x[i] - j) + min(y[i] - l[j][y[i]], r[j][y[i]] - y[i]));
    }
  }
  cout << ans;
  return 0;
}
/*

*/