#include #include #include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; using mint = atcoder::modint998244353; const ll MOD = 998244353; #define N_MAX 300002 mint inv[N_MAX],fac[N_MAX],finv[N_MAX]; void init(){ fac[0]=1;fac[1]=1; finv[0]=1;finv[1]=1; inv[1]=1; for(int i=2;i= 0); mint ans = 1; mint tmp = a; for (int i = 0; i <= 60; i++) { ll m = (ll)1 << i; if (m & n) { ans *= tmp; } tmp *= tmp; } return ans; } /** * a0+a1*(x+c)^1+ ... + an*(x+c)^nの係数を求める */ vector slide_polynomial(vector a, int c){ int n = a.size(); vector u(n), v(n); for(int i = 0; i < n; i++) { u[i] = a[i]*fac[i]; v[i] = pow(mint(c), n-i-1)*finv[n-i-1]; } auto w = atcoder::convolution(u, v); vector ans(n); for(int i = 0; i < n; i++) ans[i] = finv[i]*w[i+n-1]; return ans; } void print(vector v){ for(mint x: v) cout << x.val() << ' '; cout << endl; } int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; init(); int n; string s; cin >> n >> s; vector vi(n), vn(n); for(int i = 0; i < n; i++){ if(s[i] == 'n'){ vn[i] = 1; }else{ vi[n-i-1] = 1; } } auto v = atcoder::convolution(vn, vi); vector u(n-1); // iとnの間がk個のものがu[k]個ある for(int i = 1; i < n; i++) u[i-1] = v[i+n-1]; auto f = slide_polynomial(u, 1); int ans = 0; for(int i = 0; i < n-1; i++) ans ^= f[i].val(); cout << ans << endl; }