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())
i = min(r2, max(a, r1))
j = min(c2, max(b, c1))
ans = abs(i-a) + abs(j-b) + abs(p-i) + abs(q-j) + abs(a-p) + abs(b-q)
print(ans)