#include <bits/stdc++.h>
#include<atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll mod=998244353;
ll inf=10000000000000000;
ll ans=inf;
ll op(ll a,ll b){
    return min(a,b);
}
ll e(){
    return inf;
}
void solve(ll n,ll m,vector<ll>&x,vector<ll>&y,vector<ll>&z,vector<ll>&w,vector<vector<ll>>&memo,vector<vector<ll>>&memo2){
    vector<ll>b(1000,inf);
    segtree<ll,op,e>seg(b),seg2(b);
    for (ll i = 0; i <1000; i++)
    {
        for (ll j = 0; j < 1000; j++)
        {
            if (memo2[i][j])
            {
                seg.set(j,-i+j);
                seg2.set(j,-j-i);

            }
            if (memo[i][j])
            {
                ll q=seg.prod(j,1000);
                ans=min(ans,q-j+i);
                ll qq=seg2.prod(0,j);
                ans=min(ans,qq+j+i);
            }
        }
    }
}
int main(){
    ll n;
    cin >> n;
    vector<ll>x(n),y(n);
    vector<vector<ll>>memo(1000,vector<ll>(1000,0));
    vector<vector<ll>>memo2(1000,vector<ll>(1000,0));
    for (ll i = 0; i < n; i++)
    {
        cin >> x[i]>> y[i];
        memo[x[i]][y[i]]++;
    }
    ll m;
    cin  >> m;
    vector<ll>z(m),w(m);
    vector<vector<ll>>g(1000);
    for (ll i = 0; i < m; i++)
    {
        cin >> z[i] >> w[i];
        memo2[z[i]][w[i]]++;
    }
    solve(n,m,x,y,z,w,memo,memo2);
    solve(m,n,z,w,x,y,memo2,memo);
    cout << ans << endl;
}