from collections import deque
import sys
sys.setrecursionlimit(1 << 20)

H,W=map(int,input().split())
Si,Sj=map(int,input().split())
Gi,Gj=map(int,input().split())

d=[[1,0],[0,1],[-1,0],[0,-1]]
global ans
ans=0

seen=[[False for j in range(W)] for i in range(H)]

def dfs(x1,y1):
    global ans
    seen[x1][y1]=True
    #print(seen[0])
    #print(seen[1])
    #print("###")
    if x1==Gi-1 and y1==Gj-1:
        ans += 1
        seen[x1][y1] = False
        #print("#")
        return
    for x,y in d:
        x2=x1+x
        y2=y1+y
        if not (0<=y2<W):continue
        if not (0<=x2<H):continue
        if seen[x2][y2]:continue
        cnt=0
        for xx,yy in d:
            xt=x2+xx
            yt=y2+yy
            if not (0<=yt<W):continue
            if not (0<=xt<H):continue
            if seen[xt][yt]:cnt +=1
        if cnt>1:
            continue
        else:
            dfs(x2,y2)
    seen[x1][y1] = False
    

dfs(Si-1,Sj-1)
print(ans)