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
for r in range(r1,r2+1):
    for c in range(c1,c2+1):
        tmp = abs(A-r)+abs(B-c) + abs(r-P)+abs(c-Q) + abs(P-A)+abs(Q-B)
        ans = min(ans,tmp)
print(ans)