#include <bits/stdc++.h>
#define rep(i, p, n) for (ll i = p; i < (ll)(n); i++)
#define rep2(i, p, n) for (ll i = p; i >= (ll)(n); i--)
using namespace std;
using ll = long long;
using ld = long double;
const double pi = 3.141592653589793;
const long long inf = 2 * 1e9;
const long long linf = 4 * 1e18;
const ll mod1 = 1000000007;
const ll mod2 = 998244353;
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;
}

// atcoder
#include <atcoder/all>
using namespace atcoder;
using mint1 = modint1000000007;
using mint2 = modint998244353;

vector<pair<ll, ll>> base = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};

int main()
{

    //////////////////
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    //////////////////

    ll N;
    string S;
    cin >> N >> S;
    vector<vector<vector<mint2>>> dp(3, vector<vector<mint2>>(2, vector<mint2>(2)));
    vector<vector<vector<mint2>>> next_dp(3, vector<vector<mint2>>(2, vector<mint2>(2)));

    dp[2][0][0] = (S.at(0) != 'x');
    dp[2][0][1] = (S.at(0) != 'o');

    rep(i, 0, N - 1)
    {
        fill(next_dp.begin(), next_dp.end(), vector<vector<mint2>>(2, vector<mint2>(2)));
        if (S.at(i + 1) != 'x')
        {
            next_dp[1][0][0] += dp[0][0][0];
            next_dp[0][1][0] += dp[0][0][1];
            next_dp[1][1][0] += dp[0][1][0];
            next_dp[2][0][0] += dp[1][0][0];
            next_dp[0][0][0] += dp[1][0][1];
            next_dp[2][0][0] += dp[1][1][0];
            next_dp[0][1][0] += dp[1][1][1];
            next_dp[2][0][0] += dp[2][0][0];
            next_dp[0][0][0] += dp[2][0][1];
        }
        if (S.at(i + 1) != 'o')
        {
            next_dp[1][0][1] += dp[0][0][1];
            next_dp[0][1][1] += dp[0][0][0];
            next_dp[1][1][1] += dp[0][1][1];
            next_dp[2][0][1] += dp[1][0][1];
            next_dp[0][0][1] += dp[1][0][0];
            next_dp[2][0][1] += dp[1][1][1];
            next_dp[0][1][1] += dp[1][1][0];
            next_dp[2][0][1] += dp[2][0][1];
            next_dp[0][0][1] += dp[2][0][0];
        }
        swap(dp, next_dp);
    }

    mint2 ans = 0;
    rep(i, 0, 3) rep(j, 0, 2) rep(k, 0, 2) ans += dp[i][j][k];

    cout << ans.val() << "\n";
}