#line 1 "main.cpp"
#include <bits/stdc++.h>
#include <atcoder/all>
// #include "library/templates/template.hpp"
using namespace atcoder;
using namespace std;
using ll = long long int;

using mint = modint998244353;
mint solve(int N, string S)
{
    map<char, int> t;
    t['.'] = 0;
    t['d'] = 1;
    t['k'] = 2;
    vector<vector<mint>> dp(N + 2, vector<mint>(3, 0));
    dp[0][0] = 1;
    for (int i = 1; i <= N; i++)
    {
        // odd
        if (i % 2)
        {
            if (S[i] == '.')
            {
                if (S[i + 1] == '.')
                {
                    dp[i][0] += dp[i - 1][0];
                    dp[i][1] += dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2];
                    dp[i][2] += dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2];
                }
                else
                {
                    dp[i][0] += dp[i - 1][0];
                    dp[i][3 - t[S[i + 1]]] += dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2];
                }
            }
            else
            {
                dp[i][t[S[i]]] += dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2];
            }
        }
        else
        {
            if (S[i] == '.')
            {
                if (S[i + 1] == '.')
                {
                    dp[i][0] += dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2];
                    dp[i][1] += dp[i - 1][1] + dp[i - 1][2];
                    dp[i][2] += dp[i - 1][1] + dp[i - 1][2];
                }
                else
                {
                    dp[i][0] += dp[i - 1][0] + dp[i - 1][1] + dp[i - 1][2];
                    dp[i][3 - t[S[i + 1]]] += dp[i - 1][1] + dp[i - 1][2];
                }
            }
            else
            {
                dp[i][t[S[i]]] += dp[i - 1][1] + dp[i - 1][2];
            }
        }
    }

    mint ans = 0;
    for (int k = 0; k < 3; k++)
    {
        ans += dp[N - 2][k];
    }
    // cerr << dp << endl;
    return ans;
}

int main()
{
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);

    int N;
    cin >> N;

    string S = "";
    S += ".";
    for (int i = 0; i < N; i++)
    {
        string t;
        cin >> t;
        S += t;
    }
    S += ".";
    N = S.length();

    auto ans = solve(N, S);
    std::cout << ans.val() << '\n';
    return 0;
}