# region Template
import sys, math
sys.setrecursionlimit(10**7)
from itertools import *
from heapq import *
from collections import deque, defaultdict, Counter
from bisect import bisect_left, bisect_right
from copy import copy, deepcopy

INF, LINF, stdipt = float('inf'), 1 << 60, sys.stdin.readline
iin, mii = lambda: int(stdipt()), lambda: map(int, stdipt().split())
lmi = lambda: list(map(int, stdipt().split()))
MOD, MOD2 = 998244353, 10**9+7
# endregion

# from sortedcontainers import SortedSet, SortedList, SortedDict


def main():
    H, W = map(int, sys.stdin.readline().split())
    si, sj = map(lambda x: int(x)-1, sys.stdin.readline().split())
    gi, gj = map(lambda x: int(x)-1, sys.stdin.readline().split())

    # 移動ベクトル
    dirs = [(1,0),(-1,0),(0,1),(0,-1)]
    visited = [[False]*W for _ in range(H)]
    count = 0

    def in_grid(i, j):
        return 0 <= i < H and 0 <= j < W

    def dfs(i, j):
        nonlocal count
        if (i, j) == (gi, gj):
            count += 1
            return
        for di, dj in dirs:
            ni, nj = i + di, j + dj
            if not in_grid(ni, nj) or visited[ni][nj]:
                continue
            # 周囲4マスの訪問済みセル数を数える
            neighbor = 0
            for ddi, ddj in dirs:
                xi, xj = ni + ddi, nj + ddj
                if in_grid(xi, xj) and visited[xi][xj]:
                    neighbor += 1
            # 枝刈り条件：訪問済みは移動元セルのみ(=1) の場合のみ探索
            if neighbor == 1:
                visited[ni][nj] = True
                dfs(ni, nj)
                visited[ni][nj] = False

    # 初期化：開始セルを訪問済みにして探索スタート
    visited[si][sj] = True
    dfs(si, sj)
    print(count)

if __name__ == '__main__':
    main()