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)]

SINV=[]
for i in range(H-1,-1,-1):
    SINV.append(S[i])

flag1=1
for i in range(H):
    for j in range(W):
        if S[i][j]==T[i][j]:
            flag1=0

flag2=1
for i in range(H):
    for j in range(W):
        if SINV[i][j]==T[i][j]:
            flag2=0

ANS=0
c=1

for i in range(1,100000):
    if i%2==1 and flag1==1:
        ANS+=i*c*(1-pow(2,-(i-1)))
        c-=c*(1-pow(2,-(i-1)))

    if i%2==0 and flag2==1:
        ANS+=i*c*(1-pow(2,-(i-1)))
        c-=c*(1-pow(2,-(i-1)))

print(ANS)