#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef int64_t lint;
#define rep(i, n) for(int i=0; i<n; i++)
#define repx(i, l, n) for(int i=l; i<n; i++)
#define all(v) v.begin(), v.end()
#define show(x) cout << #x << ": " << x << endl;
#define list(x) cout << #x << ": " << x << "  ";
#define pb push_back
using vi = vector<lint>;
using vvi = vector<vector<lint>>;
template<class T> inline void vin(vector<T>& v) { rep(i, v.size()) cin >> v.at(i); }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T> inline void drop(T x) { cout << x << endl; exit(0); }
template<class T> void vout(vector<T> v) { rep(i, v.size()) { cout << v.at(i) << ' '; } cout << endl; }
constexpr lint LINF = LLONG_MAX/2;
using mint = modint998244353;
using vm = vector<mint>;

int main() {
	lint N;
	cin >> N;

	mint a=1, b=0, c=0;
	lint x, y, z;
	string s, t;
	rep(_, N) {
		cin >> t;
		s += t;
	}
	s += '#';
	std::vector<vm> dp(N*16+1, vm(3));
	dp[0][0] = 1;
	rep(i, N*16) {
		if (s[i] == 'd') {
			if (i%2 == 0) dp[i+1][1] = dp[i][0] + dp[i][1] + dp[i][2];
			else dp[i+1][1] = dp[i][1] + dp[i][2];
		}
		if (s[i] == 'k') {
			if (i%2 == 0) dp[i+1][2] = dp[i][0] + dp[i][1] + dp[i][2];
			else dp[i+1][2] = dp[i][1] + dp[i][2];
		}
		if (s[i] == '.') {
			if (i%2 == 0) {
				dp[i+1][0] = dp[i][0];
				if (s[i+1] == 'd') dp[i+1][1] = 0;
				else dp[i+1][1] = dp[i][0] + dp[i][1] + dp[i][2];
				if (s[i+1] == 'k') dp[i+1][2] = 0;
				else dp[i+1][2] = dp[i][0] + dp[i][1] + dp[i][2];
			} else {
				dp[i+1][0] = dp[i][0] + dp[i][1] + dp[i][2];
				if (s[i+1] == 'd') dp[i+1][1] = 0;
				else dp[i+1][1] = dp[i][1] + dp[i][2];
				if (s[i+1] == 'k') dp[i+1][2] = 0;
				else dp[i+1][2] = dp[i][1] + dp[i][2];
			}
		}
		// list(i)
		// list(dp[i+1][0].val())
		// list(dp[i+1][1].val())
		// show(dp[i+1][2].val())
	}
	std::cout << (dp[N*16][0]+dp[N*16][1]+dp[N*16][2]).val() << '\n';
}