Problem: You have a large rectangular board which is divided into n × m cells (the board has n rows and m columns). Each cell is either white or black.

You paint each white cell either red or blue. Obviously, the number of different ways to paint them is 2^w, where w is the number of white cells.

After painting the white cells of the board, you want to place the maximum number of dominoes on it, according to the following rules:

  * each domino covers two adjacent cells; 
  * each cell is covered by at most one domino; 
  * if a domino is placed horizontally (it covers two adjacent cells in one of the rows), it should cover only red cells; 
  * if a domino is placed vertically (it covers two adjacent cells in one of the columns), it should cover only blue cells. 



Let the value of the board be the maximum number of dominoes you can place. Calculate the sum of values of the board over all 2^w possible ways to paint it. Since it can be huge, print it modulo 998 244 353.

Input

The first line contains two integers n and m (1 ≤ n, m ≤ 3 ⋅ 10^5; nm ≤ 3 ⋅ 10^5) — the number of rows and columns, respectively.

Then n lines follow, each line contains a string of m characters. The j-th character in the i-th string is * if the j-th cell in the i-th row is black; otherwise, that character is o.

Output

Print one integer — the sum of values of the board over all 2^w possible ways to paint it, taken modulo 998 244 353.

Examples

Input


3 4
**oo
oo*o
**oo


Output


144


Input


3 4
**oo
oo**
**oo


Output


48


Input


2 2
oo
o*


Output


4


Input


1 4
oooo


Output


9

Solution (in PYTHON3):

Solution:

from bisect import *

from collections import *
from math import gcd,ceil,sqrt,floor,inf
from heapq import *
from itertools import *
from operator import add,mul,sub,xor,truediv,floordiv
from functools import *

#------------------------------------------------------------------------
import os
import sys

from io import BytesIO, IOBase
# region fastio
 
BUFSIZE = 8192
 
class FastIO(IOBase):
    newlines = 0
 
    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None
 
    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()
 
    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()
 
    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)
 
 
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")
 
 
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
 

#------------------------------------------------------------------------
def RL(): return map(int, sys.stdin.readline().rstrip().split())
def RLL(): return list(map(int, sys.stdin.readline().rstrip().split()))
def N(): return int(input())
def A(n):return [0]*n
def AI(n,x): return [x]*n
def A2(n,m): return [[0]*m for i in range(n)]
def G(n): return [[] for i in range(n)]
def GP(it): return [[ch,len(list(g))] for ch,g in groupby(it)]
#------------------------------------------------------------------------


from types import GeneratorType
 
 
def bootstrap(f, stack=[]):
    def wrappedfunc(*args, **kwargs):
        if stack:
            return f(*args, **kwargs)
        else:
            to = f(*args, **kwargs)
            while True:
                if type(to) is GeneratorType:
                    stack.append(to)
                    to = next(to)
                else:
                    stack.pop()
                    if not stack:
                        break
                    to = stack[-1].send(to)
            return to
 
    return wrappedfunc

mod=10**9+7
farr=[1]
ifa=[]
 
def fact(x,mod=0):
    if mod:
        while x>=len(farr):
            farr.append(farr[-1]*len(farr)%mod)
    else:
        while x>=len(farr):
            farr.append(farr[-1]*len(farr))
    return farr[x]
 
def ifact(x,mod):
    global ifa
    fact(x,mod)
    ifa.append(pow(farr[-1],mod-2,mod))
    for i in range(x,0,-1):
        ifa.append(ifa[-1]*i%mod)
    ifa.reverse()
 
def per(i,j,mod=0):
    if i<j: return 0
    if not mod:
        return fact(i)//fact(i-j)
    return farr[i]*ifa[i-j]%mod
    
def com(i,j,mod=0):
    if i<j: return 0
    if not mod:        
        return per(i,j)//fact(j)
    return per(i,j,mod)*ifa[j]%mod
 
def catalan(n):
    return com(2*n,n)//(n+1)
 
def isprime(n):
    for i in range(2,int(n**0.5)+1):
        if n%i==0:
            return False
    return True

def floorsum(a,b,c,n):#sum((a*i+b)//c for i in range(n+1))
    if a==0:return b//c*(n+1)
    if a>=c or b>=c: return floorsum(a%c,b%c,c,n)+b//c*(n+1)+a//c*n*(n+1)//2
    m=(a*n+b)//c
    return n*m-floorsum(c,c-b-1,a,m-1)

def inverse(a,m):
    a%=m
    if a<=1: return a
    return ((1-inverse(m,a)*m)//a)%m
 
def lowbit(n):
    return n&-n
 
class BIT:
    def __init__(self,arr):
        self.arr=arr
        self.n=len(arr)-1
        
    def update(self,x,v):
        while x<=self.n:
            self.arr[x]+=v
            x+=x&-x
 
    def query(self,x):
        ans=0
        while x:
            ans+=self.arr[x]
            x&=x-1
        return ans

class ST:
    def __init__(self,arr):#n!=0
        n=len(arr)
        mx=n.bit_length()#取不到
        self.st=[[0]*mx for i in range(n)]
        for i in range(n):
            self.st[i][0]=arr[i]
        for j in range(1,mx):
            for i in range(n-(1<<j)+1):
                self.st[i][j]=max(self.st[i][j-1],self.st[i+(1<<j-1)][j-1])
    def query(self,l,r):
        if l>r:return -inf
        s=(r+1-l).bit_length()-1
        return max(self.st[l][s],self.st[r-(1<<s)+1][s])
'''        
class DSU:#容量+路径压缩
    def __init__(self,n):
        self.c=[-1]*n
 
    def same(self,x,y):
        return self.find(x)==self.find(y)
 
    def find(self,x):
        if self.c[x]<0:
            return x
        self.c[x]=self.find(self.c[x])
        return self.c[x]
 
    def union(self,u,v):
        u,v=self.find(u),self.find(v)
        if u==v:
            return False
        if self.c[u]>self.c[v]:
            u,v=v,u
        self.c[u]+=self.c[v]
        self.c[v]=u
        return True
 
    def size(self,x): return -self.c[self.find(x)]'''
    
class UFS:#秩+路径
    def __init__(self,n):
        self.parent=[i for i in range(n)]
        self.ranks=[0]*n
 
    def find(self,x):
        if x!=self.parent[x]:
            self.parent[x]=self.find(self.parent[x])
        return self.parent[x]
 
    def union(self,u,v):
        pu,pv=self.find(u),self.find(v)
        if pu==pv:
            return False
        if self.ranks[pu]>=self.ranks[pv]:
            self.parent[pv]=pu
            if self.ranks[pv]==self.ranks[pu]:
                self.ranks[pu]+=1
        else:
            self.parent[pu]=pv
 
def Prime(n):
    c=0
    prime=[]
    flag=[0]*(n+1) 
    for i in range(2,n+1):
        if not flag[i]:
            prime.append(i)
            c+=1
        for j in range(c):
            if i*prime[j]>n: break
            flag[i*prime[j]]=prime[j]
            if i%prime[j]==0: break
    return prime
 
def dij(s,graph):
    d={}
    d[s]=0
    heap=[(0,s)]
    seen=set()
    while heap:
        dis,u=heappop(heap)
        if u in seen:
            continue
        seen.add(u)
        for v,w in graph[u]:
            if v not in d or d[v]>d[u]+w:
                d[v]=d[u]+w
                heappush(heap,(d[v],v))
    return d

def bell(s,g):#bellman-Ford
    dis=AI(n,inf)
    dis[s]=0
    for i in range(n-1):
        for u,v,w in edge:
            if dis[v]>dis[u]+w:
                dis[v]=dis[u]+w
    change=A(n)
    for i in range(n):
        for u,v,w in edge:
            if dis[v]>dis[u]+w:
                dis[v]=dis[u]+w
                change[v]=1
    return dis

def lcm(a,b): return a*b//gcd(a,b)
def lis(nums):
    res=[]
    for k in nums:
        i=bisect.bisect_left(res,k)
        if i==len(res):
            res.append(k)
        else:
            res[i]=k
    return len(res)

def RP(nums):#逆序对
    n = len(nums)
    s=set(nums)
    d={}
    for i,k in enumerate(sorted(s),1):
        d[k]=i
    bi=BIT([0]*(len(s)+1))
    ans=0
    for i in range(n-1,-1,-1):
        ans+=bi.query(d[nums[i]]-1)
        bi.update(d[nums[i]],1)
    return ans
 
class DLN:
    def __init__(self,val):
        self.val=val
        self.pre=None
        self.next=None

def nb(i,j,n,m):
    for ni,nj in [[i+1,j],[i-1,j],[i,j-1],[i,j+1]]:
        if 0<=ni<n and 0<=nj<m:
            yield ni,nj

def topo(n):
    q=deque()
    res=[]
    for i in range(1,n+1):
        if ind[i]==0:
            q.append(i)
            res.append(i)
    while q:
        u=q.popleft()
        for v in g[u]:
            ind[v]-=1
            if ind[v]==0:
                q.append(v)
                res.append(v)
    return res

@bootstrap
def gdfs(r,p):
    for ch in g[r]:
        if ch!=p:
            yield gdfs(ch,r)
    yield None


@bootstrap
def dfs(r):
    for v in range(k):
        nb=r*k+v
        #print(r,nb)
        if not vis[nb]:
            vis[nb]=1
            yield dfs(v)
            res.append(v)
    yield None

t=1
mod=998244353
for i in range(t):
    n,m=RL()
    res=[]
    for i in range(n):
        res.append(input())
    l=[[0]*m for i in range(n)]
    u=[[0]*m for i in range(n)]
    cnt=0
    for i in range(n):
        for j in range(m):
            if res[i][j]=='o':
                l[i][j]=1
                u[i][j]=1
                cnt+=1
                if i:
                    u[i][j]+=u[i-1][j]
                if j:
                    l[i][j]+=l[i][j-1]
    ans=0
    v3=pow(3,mod-2,mod)
    #print(cnt)
    for i in range(n):
        for j in range(m):
            if u[i][j]>1:
                x=u[i][j]
                w=pow(2,cnt-x,mod)
                
                if x&1:
                    ans+=w*v3%mod*(pow(2,x-1,mod)-1)%mod
                else:
                    ans+=w*(1+v3%mod*(pow(2,x-1,mod)-2))%mod
                ans%=mod
            if l[i][j]>1:
                x=l[i][j]
                w=pow(2,cnt-x,mod)
                #print(w)
                if x&1:
                    ans+=w*v3%mod*(pow(2,x-1,mod)-1)%mod
                else:
                    ans+=w*(1+v3%mod*(pow(2,x-1,mod)-2))%mod
                ans%=mod
            #print(ans,i,j)
    print(ans)
        
            

''' 
sys.setrecursionlimit(200000)
import threading
threading.stack_size(10**8)
t=threading.Thr
ead(target=main)
t.start()
t.join()
'''