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 = 10**18
for i in range(r1,r2+1):
    for j in range(c1,c2+1):
        ans = min(ans, (abs(A - i) + abs(B - j)) + (abs(i - P) + abs(j - Q)) + (abs(A - P) + abs(B - Q)))
print(ans)