H,W=map(int,input().split())
s0,s1=map(int,input().split())
g0,g1=map(int,input().split())
s0-=1;s1-=1
g0-=1;g1-=1
queue=[[(s0,s1)]]
ans=0
while queue:
    route=queue.pop()
    x,y=route[-1]
    if (x,y)==(g0,g1):
        ans+=1
    for dx,dy in ((0,1),(1,0),(0,-1),(-1,0)):
        if 0<=x+dx<H and 0<=y+dy<W and all(abs(xx-(x+dx))+abs(yy-(y+dy))>=2 for xx,yy in route[:-1]):
            queue.append(route+[(x+dx,y+dy)])
print(ans)