import sys
input = sys.stdin.readline

H,W=list(map(int,input().split()))
A,B=list(map(int,input().split()))
R1,C1,R2,C2=list(map(int,input().split()))
P,Q=list(map(int,input().split()))

ANS=1<<63

for i in range(R1,R2+1):
    for j in range(C1,C2+1):
        score=(abs(A-i)+abs(B-j))+(abs(P-i)+abs(Q-j))+(abs(A-P)+abs(B-Q))

        ANS=min(ANS,score)

print(ANS)