import sys
input = sys.stdin.readline

H,W=map(int,input().split())

S=[input().strip() for i in range(H)]
T=[input().strip() for i in range(H)]

flag=1
for i in range(H):
    for j in range(W):
        if S[i][j]==T[i][j]:
            flag=0


ANS=0
c=1
if flag:
    for i in range(1,100000):
        if i%2==1:
            ANS+=i*c*(1-pow(2,-(i-1)))
            c-=c*(1-pow(2,-(i-1)))

else:
    for i in range(1,100000):
        if i%2==0:
            ANS+=i*c*(1-pow(2,-(i-1)))
            c-=c*(1-pow(2,-(i-1)))

print(ANS)