import sys, time, random, heapq, math, itertools, copy
from collections import deque, Counter, defaultdict
#from sortedcontainers import SortedSet, SortedList
from bisect import bisect, bisect_left, bisect_right
import heapq as hq
from functools import cache, cmp_to_key
def debug(*x):print('debug:',*x, file=sys.stderr)
sys.setrecursionlimit(300000)
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 61 - 1
mod = 998244353
dir = [(0, 1), (0, -1), (1, 0), (-1, 0)]

H, W = mi()
A, B = mi()
R1, C1, R2, C2 = mi()
P, Q = mi()
musi = set()
for i in range(R1-1, R2):
    for j in range(C1-1, C2):
        musi.add((i,j))

ans = 0
d = deque()
d.append((A-1, B-1, 0))
visited = [[False] * W for _ in range(H)]
visited[A-1][B-1] = True
while d:
    i,j,cnt = d.popleft()
    if (i, j) in musi:
        ans += cnt
        break
    for di, dj in dir:
        ni, nj = i + di, j + dj
        if not(0<=ni<H and 0<=nj<W):
            continue
        if visited[ni][nj]:
            continue
        visited[ni][nj] = True
        d.append((ni, nj, cnt+1))

debug(ans)

d = deque()
d.append((i, j, 0))
visited = [[False] * W for _ in range(H)]
visited[i][j] = True
while d:
    i,j,cnt = d.popleft()
    if (i, j) == (P-1, Q-1):
        ans += cnt
        break
    for di, dj in dir:
        ni, nj = i + di, j + dj
        if not(0<=ni<H and 0<=nj<W):
            continue
        if visited[ni][nj]:
            continue
        visited[ni][nj] = True
        d.append((ni, nj, cnt+1))

debug(ans)

d = deque()
d.append((i, j, 0))
visited = [[False] * W for _ in range(H)]
visited[i][j] = True
while d:
    i,j,cnt = d.popleft()
    if (i, j) == (A-1, B-1):
        ans += cnt
        break
    for di, dj in dir:
        ni, nj = i + di, j + dj
        if not(0<=ni<H and 0<=nj<W):
            continue
        if visited[ni][nj]:
            continue
        visited[ni][nj] = True
        d.append((ni, nj, cnt+1))

print(ans)