#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

template <int64_t Modulus>
struct Modint {
    using mint = Modint;
    long long v;
    Modint() : v(0) {}
    Modint(long long x) {
        x %= Modulus;
        if (x < 0) x += Modulus;
        v = x;
    }
    const long long& val() const { return v; }
    // 代入演算子
    mint& operator+=(const mint rhs) {
        v += rhs.v;
        if (v >= Modulus) v -= Modulus;
        return *this;
    }
    mint& operator-=(const mint rhs) {
        if (v < rhs.v) v += Modulus;
        v -= rhs.v;
        return *this;
    }
    mint& operator*=(const mint rhs) {
        v = v * rhs.v % Modulus;
        return *this;
    }
    mint& operator/=(mint rhs) { return *this = *this * rhs.inv(); }
    // 累乗, 逆元
    mint pow(long long n) const {
        mint x = *this, res = 1;
        while (n) {
            if (n & 1) res *= x;
            x *= x;
            n >>= 1;
        }
        return res;
    }
    mint inv() const { return pow(Modulus - 2); }
    // 算術演算子
    mint operator+(const mint rhs) const { return mint(*this) += rhs; }
    mint operator-(const mint rhs) const { return mint(*this) -= rhs; }
    mint operator*(const mint rhs) const { return mint(*this) *= rhs; }
    mint operator/(const mint rhs) const { return mint(*this) /= rhs; }
    mint operator-() const { return mint() - *this; }  // 単項
    // 入出力ストリーム
    friend ostream& operator<<(ostream& os, const mint& p) { return os << p.v; }
    friend istream& operator>>(istream& is, mint& p) {
        long long t;
        is >> t;
        p = mint(t);
        return (is);
    }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int n; cin >> n;
    string s = "";
    rep(i,n) {
        string t; cin >> t;
        s += t;
    }

    n *= 16;
    s += '.';
    auto f = [&](char c) {
        if(c == '.') return 0;
        if(c == 'd') return 1;
        return 2;
    };

    using mint = Modint<998244353>;
    vector<vector<mint>> dp(n + 1, vector<mint>(3, 0));
    dp[0][0] = 1;
    rep(i,n) {
        if(s[i] == '.') {
            dp[i + 1][f('.')] += dp[i][f('.')];
            if(i % 2 == 1) dp[i + 1][f('.')] += dp[i][f('d')] + dp[i][f('k')];

            if(s[i + 1] != 'd') {
                if(i % 2 == 0) dp[i + 1][f('d')] += dp[i][f('.')];
                dp[i + 1][f('d')] += dp[i][f('d')] + dp[i][f('k')];
            }

            if(s[i + 1] != 'k') {
                if(i % 2 == 0) dp[i + 1][f('k')] += dp[i][f('.')];
                dp[i + 1][f('k')] += dp[i][f('d')] + dp[i][f('k')];
            }
        } else {
            if(i % 2 == 0) dp[i + 1][f(s[i])] += dp[i][f('.')];
            dp[i + 1][f(s[i])] += dp[i][f('d')] + dp[i][f('k')];
        }
    }

    cout << dp[n][f('.')] + dp[n][f('d')] + dp[n][f('k')] << endl;
}