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())
ans = 10** 18
d = abs(a - p) + abs(b - q)
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) + d)
print(ans)