def dist(pos1, pos2):
    r1, c1 = pos1
    r2, c2 = pos2
    return abs(r1 - r2) + abs(c1 - c2)


H, W = [int(s) for s in input().split()]
A, B = [int(s) for s in input().split()]
R1, C1, R2, C2 = [int(s) for s in input().split()]
P, Q = [int(s) for s in input().split()]

start = (A, B)
bugs = [(r, c) for r in range(R1, R2 + 1) for c in range(C1, C2 + 1)]
trash = (P, Q)

ans = min(dist(start, bug) + dist(bug, trash) + dist(trash, start) for bug in bugs)
print(ans)