#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353;
int n;
string s[1010];
int main(){
    ios::sync_with_stdio(0); cin.tie(0), cout.tie(0);
    cin >> n;
    for (int i = 1; i <= n; ++ i) {
        // cin >> (s[i] + 1);
        cin >> s[i]; s[i] = ' ' + s[i] + "\0\0";
    }
    for (int i = 0; i <= n + 1; ++ i) s[0][i] = s[i][0] = s[n + 1][i] = s[i][n + 1] = '.';
    long long ans = 1;
    for (int i = 1; i <= n; ++ i){
        int be = 0;
        for (int j = 1; j <= n + 1; ++ j){
            if(s[i][j] != '?'){
                if(be != j - 1 && s[i][j] == s[i][be])(ans *= (s[i][j] == '.') * (j - be)) %= MOD;
                be = j;
            }
        }
        be = 0;
        for (int j = 1; j <= n + 1; ++ j){
            if(s[j][i] != '?'){
                if(be != j - 1 && s[j][i] == s[be][i])(ans *= (s[j][i] == '.') * (j - be)) %= MOD;
                be = j;
            }
        }
    }
    cout << ans;
}