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())

rd = abs(P-A) + abs(Q-B)
ans = 1 << 60

for a in range(R1,R2+1):
    for b in range(C1,C2+1):
        d = abs(A-a) + abs(B-b) + abs(P-a) + abs(Q-b) + rd
        ans = min(ans, d)

print(ans)