def mi():return map(int,input().split())
n,m=mi()
si,sj=mi()
si,sj=si-1,sj-1
gi,gj=mi()
gi,gj=gi-1,gj-1
x=[1,0,-1,0]
y=[0,1,0,-1]
a=0
g=[[0]*m for _ in range(n)]
def v(i,j):
    if not(0<=i<n):return False
    if not(0<=j<m):return False
    return True
def s(i, j):
    global a
    if (i,j)==(gi,gj):
        a+=1
        return
    for k in range(4):
        ni,nj=i+x[k],j+y[k]
        if not v(ni,nj):continue
        if g[ni][nj]:continue
        ne=0
        for l in range(4):
            pi,pj=ni+x[l],nj+y[l]
            if not v(pi,pj):continue
            if g[pi][pj]:ne+= 1
        if ne==1:
            g[ni][nj]=1
            s(ni,nj)
            g[ni][nj]=0

g[si][sj] = 1
s(si,sj)
print(a)