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

dy = [-1,1,0,0]
dx = [0,0,-1,1]
visited = [[False for _ in range(W)] for _ in range(H)]
ans = 0
def f(y,x):
    if(y == gy and x == gx):
        global ans
        ans += 1
        return

    visited[y][x] = True

    for i in range(4):
        next_y = y + dy[i]
        next_x = x + dx[i]
        if(next_y < 0 or H <= next_y):continue
        if(next_x < 0 or W <= next_x):continue
        if(visited[next_y][next_x]):continue
        
        count = 0
        for j in range(4):
            next_next_y = next_y + dy[j]
            next_next_x = next_x + dx[j]
            if(next_next_y < 0 or H <= next_next_y):continue
            if(next_next_x < 0 or W <= next_next_x):continue
            count += visited[next_next_y][next_next_x]

        if(count >= 2):continue
        f(next_y,next_x)

    visited[y][x] = False    

f(sy,sx)
print(ans)