from collections import deque

def check(order):
    field = [[1 for _ in range(W)] for _ in range(H)]
    for o in order:
        i, j = o
        field[i][j] = 0
    global si, sj
    global gi, gj
    deq = deque()
    deq.append((si, sj))
    dist = [[INF for _ in range(W)] for _ in range(H)]
    dist[si][sj] = 0
    while deq:
        i, j = deq.popleft()
        for di, dj in dir:
            ni = i+di
            nj = j+dj
            if 0<=ni<H and 0<=nj<W and field[ni][nj]==0:
                if dist[ni][nj]>dist[i][j]+1:
                    dist[ni][nj] = dist[i][j]+1
                    deq.append((ni, nj))
    if len(order)-1==dist[gi][gj]:
        return True
    else:
        return False
    
def dfs(i, j, order):
    global gi, gj
    if i==gi and j==gj:
        if check(order):
            ans.add(tuple(order))
        return
    for di, dj in dir:
        ni = i+di
        nj = j+dj
        if 0<=ni<H and 0<=nj<W and seen[ni][nj]==0:
            tmp = 0
            for ddi, ddj in dir:
                nni = ni+ddi
                nnj = nj+ddj
                if 0<=nni<H and 0<=nnj<W:
                    if (nni, nnj) in order:
                        tmp+=1
            if tmp<=1:
                order.append((ni, nj))
                seen[ni][nj] = 1
                dfs(ni, nj, order)
                order.pop()
                seen[ni][nj] = 0

INF = 10**9
import sys
import pypyjit
pypyjit.set_param('max_unroll_recursion=-1')
input = sys.stdin.readline
H, W = map(int, input().split())
si, sj = map(int, input().split())
gi, gj = map(int, input().split())
si-=1
sj-=1
gi-=1
gj-=1
dir = [(0, 1), (1, 0), (-1, 0), (0, -1)]
seen = [[0 for _ in range(W)] for _ in range(H)]
seen[si][sj] = 1
ans = set()
order = [(si, sj)]
dfs(si, sj, order)
print(len(ans))