import sys
input = sys.stdin.readline

from collections import deque

DP=[[1<<30]*1010 for i in range(1010)]
Q=deque()
N=int(input())

for i in range(N):
    x,y=map(int,input().split())
    DP[x][y]=0
    Q.append((x,y))

while Q:
    x,y=Q.popleft()
    for z,w in [(x+1,y),(x-1,y),(x,y+1),(x,y-1)]:
        if 0<=z<1010 and 0<=w<1010:
            if DP[z][w]>DP[x][y]+1:
                DP[z][w]=DP[x][y]+1
                Q.append((z,w))

M=int(input())
ANS=1<<30

for i in range(M):
    x,y=map(int,input().split())
    ANS=min(ANS,DP[x][y])

print(ANS)