H,W=map(int,input().split())
a,b=map(int,input().split())
x0,y0,x1,y1=map(int,input().split())
p,q=map(int,input().split())
score=10**10
for x in range(x0,x1+1):
  for y in range(y0,y1+1):
    ans=abs(a-x)+abs(b-y)+abs(p-x)+abs(q-y)
    score=min(score,ans)
print(score+abs(p-a)+abs(q-b))