M=998244353
n,m=map(int,input().split())
p=[*range(n*m)]
c=[1]*n*m
def R(x):
    while x!=p[x]:x=p[x]
    return x
def U(u,v):
    u,v=R(u),R(v)
    if u==v:return 499122177
    if c[u]<c[v]:u,v=v,u
    c[u]+=c[v];p[v]=p[u]
    return 1
d="."*m
r=1
for i in range(0,n*m,m):
    s=input()+"."
    for j in range(m):
        if s[j]=="#":
            r=4*r%M
            if s[j+1]=="#":r=r*U(i+j,i+j+1)%M
            if d[j]=="#":r=r*U(i+j,i+j-m)%M
    d=s
print(r)