#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
int main () {
	int N;
	cin >> N;
	string s;
	cin >> s;
	mint dp[150000];
	for (auto& a: dp) {
		a = 0;
	}
	dp[0] = 1;
	for (int i = 0; i < N; i ++) {
		for (int k = 1; i + 10 * k <= N; k ++) {
			if (s[i] == 'o' && s[i+2*k] == 'o' && s[i+5*k] == 'o' && s[i+10*k] == 'o') {
				dp[i + 10*k] += dp[i];
			}
		}
	}
	cout << dp[N].val() << endl;
}