#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int n; cin >> n;
	vector<int> x(n), y(n);
	rep(i,0,n){
		cin >> x[i] >> y[i];
	}

	int m; cin >> m;
	vector<int> z(m), w(m);
	rep(i,0,m){
		cin >> z[i] >> w[i];
	}

	const int mx = 1001;
	vector<vector<int>> dp1(mx, vector<int>(mx,1e9));
	vector<vector<int>> dp2(mx, vector<int>(mx,1e9));
	vector<vector<int>> dp3(mx, vector<int>(mx,1e9));
	vector<vector<int>> dp4(mx, vector<int>(mx,1e9));

	rep(i,0,n){
		dp1[x[i]][y[i]] = 0;
		dp2[x[i]][y[i]] = 0;
		dp3[x[i]][y[i]] = 0;
		dp4[x[i]][y[i]] = 0;
	}

	rep(i,0,mx-1){
		rep(j,0,mx){
			chmin(dp1[i+1][j], dp1[i][j]+1);
			chmin(dp2[i+1][j], dp2[i][j]+1);
		}
	}

	rrep(i,1,mx){
		rrep(j,0,mx){
			chmin(dp3[i-1][j], dp3[i][j]+1);
			chmin(dp4[i-1][j], dp4[i][j]+1);
		}
	}

	rep(i,0,mx){
		rep(j,0,mx-1){
			chmin(dp1[i][j+1], dp1[i][j]+1);
			chmin(dp3[i][j+1], dp3[i][j]+1);
		}
	}

	rrep(i,0,mx){
		rrep(j,1,mx){
			chmin(dp2[i][j-1], dp2[i][j]+1);
			chmin(dp4[i][j-1], dp4[i][j]+1);
		}
	}

	int ans = 1e9;
	rep(i,0,m){
		vector<int> v = {
			dp1[z[i]][w[i]],
			dp2[z[i]][w[i]],
			dp3[z[i]][w[i]],
			dp4[z[i]][w[i]]
		};
		chmin(ans, min(v));
	}
	cout << ans << '\n';



}