import collections
import sys
sys.setrecursionlimit(10**5)
H,W = map(int,input().split())
Si,Sj = map(int,input().split())
Gi,Gj = map(int,input().split())
ans = 0
S = set()
WW = 100
S.add(Si*WW+Sj)
D = collections.deque()
D.append([Si,Sj])
X = [1,0,-1,0]
Y = [0,1,0,-1]
ans = 0
def dfs():
    global ans
    if D[-1]==[Gi,Gj]:
        ans+=1
    else:
        i,j = D[-1]
        for x,y in zip(X,Y):
            ni = i+x
            nj = j+y
            if 1<=ni<=H and 1<=nj<=W and not ni*WW+nj in S:
                S.remove(i*WW+j)
                if not (ni*WW+nj+1 in S or (ni+1)*WW+nj in S or (ni-1)*WW+nj in S or ni*WW+nj-1 in S):
                    S.add(i*WW+j)
                    D.append([ni,nj])
                    S.add(ni*WW+nj)
                    dfs()
                    D.pop()
                    S.remove(ni*WW+nj)
                S.add(i*WW+j)

dfs()
print(ans)