import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.TreeSet;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		int[] x = new int[n];
		int[] y = new int[n];
		for (int i = 0; i < n; i++) {
			String[] sa = br.readLine().split(" ");
			x[i] = Integer.parseInt(sa[0]);
			y[i] = Integer.parseInt(sa[1]);
		}

		List<TreeSet<Integer>> list = new ArrayList<>(1000);
		for (int i = 0; i < 1000; i++) {
			list.add(new TreeSet<>());
		}

		int m = Integer.parseInt(br.readLine());
		for (int i = 0; i < m; i++) {
			String[] sa = br.readLine().split(" ");
			int z = Integer.parseInt(sa[0]);
			int w = Integer.parseInt(sa[1]);
			list.get(z).add(w);
		}
		br.close();

		int ans = 10000;
		for (int i = 0; i < n; i++) {
			int xi = x[i];
			int yi = y[i];
			int start = Math.max(xi - ans, 0);
			int end = Math.min(xi + ans, 999);
			for (int j = start; j <= end; j++) {
				int xj = Math.abs(xi - j);
				TreeSet<Integer> set = list.get(j);
				Integer e = set.floor(yi);
				if (e != null) {
					ans = Math.min(ans, xj + yi - e);
				}
				e = set.ceiling(yi);
				if (e != null) {
					ans = Math.min(ans, xj + e - yi);
				}
			}
		}
		System.out.println(ans);
	}
}