def manh(x1, y1, x2, y2):
    return abs(x2-x1) + abs(y2-y1)

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 = H*W
for x in range(R1, R2+1):
    for y in range(C1, C2+1):
        tmp = manh(A,B,x,y) + manh(P,Q,x,y) + manh(A,B,P,Q)
        ans = min(ans, tmp)

print(ans)