H, W = map(int, input().split())
A, B = map(int, input().split())
R1, C1, R2, C2 = map(int, input().split())
P, Q = map(int, input().split())
res = 10 ** 9
for r in range(R1, R2 + 1):
    for c in range(C1, C2 + 1):
        time = 0
        time = abs(A - r) + abs(B - c) + abs(P - r) + abs(Q - c) + abs(A - P) + abs(B - Q)
        res = min(res, time) 

print(res)