mod=998244353
#N,Q=map(int, input().split())
import heapq 
from heapq import heappop,heappush,heapify
from sys import stdin, setrecursionlimit
input = stdin.readline
readline = stdin.readline

H,W=map(int, input().split())
sy,sx=map(int, input().split())
gy,gx=map(int, input().split())
sy-=1;sx-=1;gy-=1;gx-=1
from collections import deque
d=deque()

C=[0]*(H*W)
s=sy*W+sx
C[s]=1
d.append((C,sy,sx))
dx,dy=[1,-1,0,0],[0,0,1,-1]
ans=0
for t in range(230):
  nd=deque()
  while d:
    C,y,x=d.popleft()
    for i in range(4):
      ny,nx=y+dy[i],x+dx[i]
      if 0<=ny<H and 0<=nx<W:
        if C[ny*W+nx]==1:
          continue
        f=1
        for j in range(4):
          nny,nnx=ny+dy[j],nx+dx[j]
          if 0<=nny<H and 0<=nnx<W:
            if y==nny and x==nnx:
              continue 
            c=nny*W+nnx 
            if C[c]==1:
              f=0
          if f==0:
            break 
        if f==1:
          if ny==gy and nx==gx:
            ans+=1
          else:
            c=ny*W+nx 
            CC=C.copy()
            CC[c]=1
            nd.append((CC,ny,nx))
  d=nd 
print(ans)