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 JAVA):

Solution:
import java.util.*;
import java.io.*;

import static java.lang.Math.*;

public class Main
{
    static MyScanner scan;
    static PrintWriter pw;
    static long MOD = 998244353;
    static long INF = 2_000_000_000_000_000_000L;
    static long inf = 2_000_000_000;
    public static void main(String[] args) {
        new Thread(null, null, "_", 1 << 27) {
            public void run() {
                try {
                    solve();
                } catch (Exception e) {
                    e.printStackTrace();
                    System.exit(1);
                }
            }
        }.start();
    }


    static void solve() throws java.lang.Exception {
        //initIo(true, "");
        initIo(false, "");
        StringBuilder sb = new StringBuilder();
        long p2[] = new long[300001];
        p2[0] = 1;
        for(int i=1;i<=300000;i++) {
            p2[i] = (p2[i-1] + p2[i-1]);
            if(p2[i]>=MOD) {
                p2[i]-=MOD;
            }
        }

        long dp[] = new long[300001];
        dp[2] = 1;
        for(int i=3;i<=300000;i++) {
            dp[i] = (dp[i-1] + 2*dp[i-2] + p2[i-2])%MOD;
            // dp[i] is number sum of max values over a stripe of length i.
            // There are three possible cases:
            // 1. End with a 'W' -> dp[i-1], because we only need 'R'
            // 2. End with a 'RR' -> dp[i-2] + 2^(i-2) as the last 'RR' domino occurs in 2^(i-2) colorings
            // 2. End with a 'WR' -> dp[i-2] as in this case the last two cells don't contribute anything
            // So, dp[i] = dp[i-1] + 2*dp[i-2] + 2^(i-2)
            // After this we need to independently solve the horiz and vertical stripes because they are non-overlapping
            // since in horiz we consider 'R' and in ver we consider 'W'
        }
        int t = 1;
        while (t-->0) {
            int n = ni(), m = ni(), w = 0;
            char mat[][] = new char[n][m];
            for(int i=0;i<n;i++) {
                mat[i] = ne().toCharArray();
                for(int j=0;j<m;++j) {
                    if(mat[i][j]=='o') {
                        ++w;
                    }
                }
            }

            long ans = 0;
            for(int ROW=0;ROW<n;++ROW) {
                for(int COL=0;COL<m;++COL) {
                    if(mat[ROW][COL]=='o') {
                        int cnt = 1;
                        while (COL+1<m && mat[ROW][COL+1]=='o') {
                            cnt++;
                            COL++;
                        }
                        ans = (ans + dp[cnt] * p2[w-cnt])%MOD;
                    }
                }
            }

            for(int COL=0;COL<m;++COL) {
                for(int ROW=0;ROW<n;++ROW) {
                    if(mat[ROW][COL]=='o') {
                        int cnt = 1;
                        while (ROW+1<n && mat[ROW+1][COL]=='o') {
                            ++cnt;
                            ++ROW;
                        }
                        ans = (ans + dp[cnt] * p2[w-cnt])%MOD;
                    }
                }
            }

            pl(ans);
        }

        pw.flush();
        pw.close();
    }

    static void assert_in_range(String varName, int n, int l, int r) {
        if (n >=l && n<=r) return;
        System.out.println(varName + " is not in range. Actual: "+n+" l : "+l+" r: "+r);
        System.exit(1);
    }
    static void assert_in_range(String varName, long n, long l, long r) {
        if (n>=l && n<=r) return;
        System.out.println(varName + " is not in range. Actual: "+n+" l : "+l+" r: "+r);
        System.exit(1);
    }

    static void initIo(boolean isFileIO, String suffix) throws IOException {
        scan = new MyScanner(isFileIO, suffix);
        if(isFileIO) {
            pw = new PrintWriter("/Users/amandeep/Desktop/output"+suffix+".txt");
        }
        else {
            pw = new PrintWriter(System.out, true);
        }
    }
    static int ni() throws IOException
    {
        return scan.nextInt();
    }
    static long nl() throws IOException
    {
        return scan.nextLong();
    }
    static double nd() throws IOException
    {
        return scan.nextDouble();
    }
    static String ne() throws IOException
    {
        return scan.next();
    }
    static String nel() throws IOException
    {
        return scan.nextLine();
    }
    static void pl()
    {
        pw.println();
    }
    static void p(Object o)
    {
        pw.print(o+" ");
    }
    static void pl(Object o)
    {
        pw.println(o);
    }
    static void psb(StringBuilder sb)
    {
        pw.print(sb);
    }
    static void pa(String arrayName, Object arr[])
    {
        pl(arrayName+" : ");
        for(Object o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, int arr[])
    {
        pl(arrayName+" : ");
        for(int o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, long arr[])
    {
        pl(arrayName+" : ");
        for(long o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, double arr[])
    {
        pl(arrayName+" : ");
        for(double o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, char arr[])
    {
        pl(arrayName+" : ");
        for(char o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, boolean arr[])
    {
        pl(arrayName+" : ");
        for(boolean o : arr)
            p(o);
        pl();
    }
    static void pa(String listName, List list)
    {
        pl(listName+" : ");
        for(Object o : list)
            p(o);
        pl();
    }
    static void pa(String arrayName, Object[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(Object o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, int[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(int o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, long[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(long o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, char[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(char o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, double[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(double o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, boolean[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(boolean o : arr[i])
                p(o);
            pl();
        }
    }
    static class MyScanner
    {
        BufferedReader br;
        StringTokenizer st;
        MyScanner(boolean readingFromFile, String suffix) throws IOException
        {
            if(readingFromFile) {
                br = new BufferedReader(new FileReader("/Users/amandeep/Desktop/input"+suffix+".txt"));
            }
            else {
                br = new BufferedReader(new InputStreamReader(System.in));
            }
        }
        String nextLine()throws IOException
        {
            return br.readLine();
        }
        String next() throws IOException
        {
            if(st==null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }
        int nextInt() throws IOException
        {
            return Integer.parseInt(next());
        }
        long nextLong() throws IOException
        {
            return Long.parseLong(next());
        }
        double nextDouble() throws IOException
        {
            return Double.parseDouble(next());
        }
    }
}