H,W=map(int,input().split())
si,sj=map(int,input().split())
si-=1
sj-=1
gi,gj=map(int,input().split())
gi-=1
gj-=1

grid=[[False]*W for _ in range(H)]

ans=0
didj=((0,1),(1,0),(0,-1),(-1,0))
def dfs(ci,cj):
    if ci==gi and cj==gj:
        global ans
        ans+=1
        return
    for di,dj in didj:
        ni=ci+di
        nj=cj+dj
        if not(0<=ni<H and 0<=nj<W):
            continue
        if grid[ni][nj]:
            continue
        gc=0
        for ddi,ddj in didj:
            nni=ni+ddi
            nnj=nj+ddj
            if not(0<=nni<H and 0<=nnj<W):
                continue
            if grid[nni][nnj]:
                gc+=1
        if gc>=2:
            continue
        grid[ni][nj]=True
        dfs(ni,nj)
        grid[ni][nj]=False

grid[si][sj]=True
dfs(si,sj)

print(ans)