H,W=map(int,input().split())
sx,sy=map(int,input().split())
gx,gy=map(int,input().split())
sx-=1
sy-=1
gx-=1
gy-=1

def dfs(px,py):
  global a
  if (px,py)==(gx,gy):
    a+=1
  else:
    for dx,dy in [(1,0),(0,1),(-1,0),(0,-1)]:
      tx,ty=px+dx,py+dy
      if 0<=tx<H and 0<=ty<W and v[tx][ty]==0:
        f=1
        for dx2,dy2 in [(1,0),(0,1),(-1,0),(0,-1)]:
          ux,uy=tx+dx2,ty+dy2
          if 0<=ux<H and 0<=uy<W and v[ux][uy]!=0:
            if v[ux][uy]<v[px][py]:
              f=0
              break
        if f:
          v[tx][ty]=v[px][py]+1
          dfs(tx,ty)
  v[px][py]=0
  return

a=0
v=[[0]*W for i in range(H)]
v[sx][sy]=1
dfs(sx,sy)
print(a)