#include <bits/stdc++.h>
using namespace std;
using ll=long long;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}

#include <atcoder/modint>
using mint = atcoder::modint998244353;

void solve();
// CITRUS CURIO CITY / FREDERIC
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    int N;
    cin >> N;
    string S;
    cin >> S;
    vector dp(2, vector(2, vector(3, vector<mint>(2))));
    if (S[0] != 'o') dp[0][0][0][0]++;
    if (S[0] != 'x') dp[1][0][0][0]++;
    rep(i, 1, N){
        vector n_dp(2, vector(2, vector(3, vector<mint>(2))));
        rep(a, 0, 2) rep(b, 0, 2) rep(c, 0, 3) rep(d, 0, 2){
            if (S[i] != 'o'){
                if (a == 1){
                    int nb = b;
                    if (c == 0) nb++;
                    if (c == 2 || d == 0) nb = 0;
                    if (nb < 2){
                        n_dp[a ^ 1][nb][0][1] += dp[a][b][c][d];
                    }
                }
                else{
                    n_dp[a][b][min(c + 1, 2)][d] += dp[a][b][c][d];
                }
            }
            if (S[i] != 'x'){
                if (a == 0){
                    int nb = b;
                    if (c == 0) nb++;
                    if (c == 2 || d == 0) nb = 0;
                    if (nb < 2){
                        n_dp[a ^ 1][nb][0][1] += dp[a][b][c][d];
                    }
                }
                else{
                    n_dp[a][b][min(c + 1, 2)][d] += dp[a][b][c][d];
                }
            }
        }
        swap(n_dp, dp);
    }
    mint ans = 0;
    for (auto x : dp) for (auto y : x) for (auto z : y) for (auto w : z) ans += w;
    cout << ans.val() << "\n";
    /*
    int N;
    cin >> N;
    int ans = 0;
    rep(i, 0, 1 << N){
        vector<int> p;
        int tmp = i;
        rep(j, 0, N){
            p.push_back(tmp & 1);
            tmp /= 2;
        }
        ans++;
        vector<int> q;
        for (int l = 0, r = 0; l < N; l = r){
            while (r < N && p[l] == p[r]) r++;
            q.push_back(r - l);
        }
        int R = 0;
        rep(j, 1, q.size() - 1){
            if (q[j] == 1) R++;
            if (q[j] > 2) R = 0;
            if (R == 2){
                ans--;
                break;
            }
        }
    }
    cout << ans << "\n";*/
}