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
ans = 0
visited = [[0 for _ in range(W)] for _ in range(H)]
visited[si][sj] = 1
def dfs(i,j):
    global ans
    if i==gi and j==gj:
        ans += 1
        visited[i][j] = 0
        return
    for di,dj in [(-1,0),(1,0),(0,-1),(0,1)]:
        ni,nj = i+di,j+dj
        if 0<=ni<H and 0<=nj<W and visited[ni][nj]==0:
            cnt = 0
            for di1,dj1 in [(-1,0),(1,0),(0,-1),(0,1)]:
                ni1,nj1 = ni+di1,nj+dj1
                if 0<=ni1<H and 0<=nj1<W and visited[ni1][nj1]==1:
                    cnt += 1
            if cnt<2:
                visited[ni][nj] = 1
                dfs(ni,nj)
    visited[i][j] = 0
    return
dfs(si,sj)
print(ans)