#include <iostream>
using namespace std;
typedef long long ll;

const ll MOD = 998244353;

ll dp[200005][3];

int main()
{
    int n;
    cin >> n;
    string s = ".";
    for(int i = 0; i < n; i++){
        string t;
        cin >> t;
        s += t;
    }
    n = n * 16 + 1;
    dp[0][2] = 1;
    for(int i = 1; i < n; i++){
        if(s[i] == 'd'){
            if(s[i - 1] == '.'){
                if(i % 2) dp[i][0] = (dp[i - 1][1] + dp[i - 1][2]) % MOD;
                else dp[i][0] = dp[i - 1][1];
            }
            else dp[i][0] = (dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2]) % MOD;
        }
        if(s[i] == 'k'){
            if(s[i - 1] == '.'){
                if(i % 2) dp[i][1] = (dp[i - 1][0] + dp[i - 1][2]) % MOD;
                else dp[i][1] = dp[i - 1][0];
            }
            else dp[i][0] = (dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2]) % MOD;
        }
        if(s[i] == '.'){
            if(i % 2){
                dp[i][0] = (dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2]) % MOD;
                dp[i][1] = (dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2]) % MOD;
                dp[i][2] = dp[i - 1][2];
            }
            else{
                dp[i][0] = (dp[i - 1][0] + dp[i - 1][1]) % MOD;
                dp[i][1] = (dp[i - 1][0] + dp[i - 1][1]) % MOD;
                dp[i][2] = (dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2]) % MOD;
            }
        }
    }
    cout << (dp[n - 1][0] + dp[n - 1][1] + dp[n - 1][2]) % MOD << endl;
}