#include <bits/stdc++.h> using namespace std; using ll = long long; #define ALL(v) v.begin(),v.end() #define dbg(x) cerr << #x << ": " << (x) << endl; int n,m; int siz = 1e3; vector<pair<int,int>> xy, wz; int main() { cin >> n; xy.resize(n); for (auto& [x,y] : xy) { cin >> x >> y; } cin >> m; wz.resize(m); for (auto& [x,y] : wz) { cin >> x >> y; } vector<vector<int>> dis(siz, vector<int>(siz, 1e9)); queue<pair<int,int>> q; for (auto [x,y] : xy) { dis[y][x] = 0; q.emplace(x,y); } int dx[] = {-1,0,1,0,-1}; while (q.size()) { auto [x,y] = q.front(); q.pop(); for (int i = 0; i < 4; ++i) { int nx = x + dx[i]; int ny = y + dx[i+1]; if (!(0 <= nx && nx < siz && 0 <= ny && ny < siz)) continue; if (dis[ny][nx] > dis[y][x] + 1) { dis[ny][nx] = dis[y][x] + 1; q.emplace(nx, ny); } } } int ans = 1e9; for (auto [x,y] : wz) { ans = min(ans, dis[y][x]); } cout << ans << '\n'; }