from collections import deque
H, W = map(int, input().split())
A, B = map(int, input().split())
A -= 1
B -= 1
R1, C1, R2, C2 = map(int, input().split())
R1, C1, R2, C2 = R1 - 1, C1 - 1, R2 - 1, C2 - 1
P, Q = map(int, input().split())
P -= 1
Q -= 1

room = [[False]*W for _ in range(H)]
for i in range(H):
    for j in range(W):
        if R1 <= i <= R2 and C1 <= j <= C2:
            room[i][j] = True

q = deque()
q.append([A, B])
while q:
    r, c = q.popleft()
    if room[r][c]:
        ar, ac = r, c
        break
    else:
        for di, dj in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
            ni, nj = r + di, c + dj
            if not(0 <= ni < H and 0 <= nj < W):
                continue
            q.append([ni, nj])

def dist(x, y, dx, dy):
    return abs(x - dx) + abs(y - dy)

print(dist(A, B, ar, ac) + dist(ar, ac, P, Q) + dist(P, Q, A, B))