#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using mint = atcoder::modint998244353;
#define rep(i,n) for(int i=0;i<n;++i)
int main() {
    int n; cin >> n;
    string s;
    rep(i,n) {
        string t; cin >> t;
        s += t;
    }
    n *= 16;
    s += '.';

    const string notes = ".dk";
    auto idx = [&](char c) { rep(i,3)if (notes[i] == c)return i; };
    vector<vector<mint>> dp(3, vector<mint>(n + 1));
    dp[0][0] = 1;
    rep(i,n) {
        if (s[i] == '.') {
            // . 
            {
                dp[0][i + 1] += dp[0][i];
                if (i % 2 == 1)dp[0][i + 1] += dp[1][i] + dp[2][i];
            }
            // d
            if (s[i + 1] != 'd') {
                if (i % 2 == 0)dp[1][i + 1] += dp[0][i];
                dp[1][i + 1] += dp[1][i] + dp[2][i];
            }
            // k
            if (s[i + 1] != 'k') {
                if (i % 2 == 0)dp[2][i + 1] += dp[0][i];
                dp[2][i + 1] += dp[1][i] + dp[2][i];
            }
        }
        else {
            if (i % 2 == 0)dp[idx(s[i])][i + 1] += dp[0][i];
            dp[idx(s[i])][i + 1] += dp[1][i] + dp[2][i];
        }
    }

    cout << (dp[0][n] + dp[1][n] + dp[2][n]).val() << "\n";
    
    return 0;
}