h,w = map(int,input().split())
s = "".join(input() for _ in range(h))
t = "".join(input() for _ in range(h))
f1 = any(u==v=="#" for u,v in zip(s,t))^1
f2 = any(u==v=="#" for u,v in zip(s[::-1],t))^1
x = p = 0
for i in range(1,21):
    if i%2:
        if f1: x += i*(1-p)*(1-2**(1-i)); p += (1-p)*(1-2**(1-i))
    else:
        if f2: x += i*(1-p)*(1-2**(1-i)); p += (1-p)*(1-2**(1-i))
print(x)