import sys

sys.setrecursionlimit(10**5)

ways = set([(0, 1), (0, -1), (1, 0), (-1, 0)])

H, W = map(int, input().split())
S_i, S_j = map(lambda x: int(x) - 1, input().split())
G_i, G_j = map(lambda x: int(x) - 1, input().split())

grid = [[0 for _ in range(W)] for _ in range(H)]

ans = 0


def next_hop(now_i, now_j):
    for di, dj in ways:
        next_i, next_j = now_i + di, now_j + dj
        if 0 <= next_i < H and 0 <= next_j < W:
            yield next_i, next_j


def dfs(now_i, now_j):
    global ans

    if now_i == G_i and now_j == G_j:
        ans += 1
        return

    grid[now_i][now_j] += 1
    for next_i, next_j in next_hop(now_i, now_j):
        grid[next_i][next_j] += 1

    for next_i, next_j in next_hop(now_i, now_j):
        if grid[next_i][next_j] <= 1:
            dfs(next_i, next_j)

    grid[now_i][now_j] -= 1
    for next_i, next_j in next_hop(now_i, now_j):
        grid[next_i][next_j] -= 1


dfs(S_i, S_j)

print(ans)