n, m = map(int, input().split())

si, sj = map(lambda x: int(x) - 1, input().split())
gi, gj = map(lambda x: int(x) - 1, input().split())

dx4 = [1, 0, -1, 0]
dy4 = [0, 1, 0, -1]

# 0 = blank, 1 = wall
ans = 0
grid = [[0] * m for _ in range(n)]

def valid(i, j):
    if not (0 <= i < n): return False
    if not (0 <= j < m): return False
    return True

def solve(i, j):
    global ans

    if i == gi and j == gj:
        ans += 1
        return

    for k in range(4):
        ni, nj = i + dx4[k], j + dy4[k]
        if not valid(ni, nj): continue
        if grid[ni][nj]: continue
        neighbor = 0

        for l in range(4):
            pi, pj = ni + dx4[l], nj + dy4[l]
            if not valid(pi, pj): continue
            if grid[pi][pj]: neighbor += 1

        if neighbor == 1:
            grid[ni][nj] = 1
            solve(ni, nj)
            grid[ni][nj] = 0

grid[si][sj] = 1
solve(si, sj)
print(ans)