#include using namespace std; using int64 = long long; // const int mod = 1e9 + 7; const int mod = 998244353; const int64 infll = (1LL << 62) - 1; const int inf = (1 << 30) - 1; struct IoSetup { IoSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup; template< typename T1, typename T2 > ostream &operator<<(ostream &os, const pair< T1, T2 > &p) { os << p.first << " " << p.second; return os; } template< typename T1, typename T2 > istream &operator>>(istream &is, pair< T1, T2 > &p) { is >> p.first >> p.second; return is; } template< typename T > ostream &operator<<(ostream &os, const vector< T > &v) { for(int i = 0; i < (int) v.size(); i++) { os << v[i] << (i + 1 != v.size() ? " " : ""); } return os; } template< typename T > istream &operator>>(istream &is, vector< T > &v) { for(T &in : v) is >> in; return is; } template< typename T1, typename T2 > inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } template< typename T1, typename T2 > inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); } template< typename T = int64 > vector< T > make_v(size_t a) { return vector< T >(a); } template< typename T, typename... Ts > auto make_v(size_t a, Ts... ts) { return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...)); } template< typename T, typename V > typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) { t = v; } template< typename T, typename V > typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) { for(auto &e : t) fill_v(e, v); } template< typename F > struct FixPoint : F { explicit FixPoint(F &&f) : F(forward< F >(f)) {} template< typename... Args > decltype(auto) operator()(Args &&... args) const { return F::operator()(*this, forward< Args >(args)...); } }; template< typename F > inline decltype(auto) MFP(F &&f) { return FixPoint< F >{forward< F >(f)}; } template< int mod > struct ModInt { int x; ModInt() : x(0) {} ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} ModInt &operator+=(const ModInt &p) { if((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (int) (1LL * x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } ModInt inverse() const { int a = x, b = mod, u = 1, v = 0, t; while(b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } ModInt pow(int64_t n) const { ModInt ret(1), mul(x); while(n > 0) { if(n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { int64_t t; is >> t; a = ModInt< mod >(t); return (is); } static int get_mod() { return mod; } }; using modint = ModInt< mod >; template< typename T > struct Enumeration { private: static vector< T > _fact, _finv, _inv; inline static void expand(size_t sz) { if(_fact.size() < sz + 1) { int pre_sz = max(1, (int) _fact.size()); _fact.resize(sz + 1, T(1)); _finv.resize(sz + 1, T(1)); _inv.resize(sz + 1, T(1)); for(int i = pre_sz; i <= sz; i++) { _fact[i] = _fact[i - 1] * T(i); } _finv[sz] = T(1) / _fact[sz]; for(int i = (int) sz - 1; i >= pre_sz; i--) { _finv[i] = _finv[i + 1] * T(i + 1); } for(int i = pre_sz; i <= sz; i++) { _inv[i] = _finv[i] * _fact[i - 1]; } } } public: explicit Enumeration(size_t sz = 0) { expand(sz); } static inline T fact(int k) { expand(k); return _fact[k]; } static inline T finv(int k) { expand(k); return _finv[k]; } static inline T inv(int k) { expand(k); return _inv[k]; } static T P(int n, int r) { if(r < 0 || n < r) return 0; return fact(n) * finv(n - r); } static T C(int p, int q) { if(q < 0 || p < q) return 0; return fact(p) * finv(q) * finv(p - q); } static T H(int n, int r) { if(n < 0 || r < 0) return 0; return r == 0 ? 1 : C(n + r - 1, r); } }; template< typename T > vector< T > Enumeration< T >::_fact = vector< T >(); template< typename T > vector< T > Enumeration< T >::_finv = vector< T >(); template< typename T > vector< T > Enumeration< T >::_inv = vector< T >(); template< typename Mint > struct NumberTheoreticTransformFriendlyModInt { vector< Mint > dw, idw; int max_base; Mint root; NumberTheoreticTransformFriendlyModInt() { const unsigned mod = Mint::get_mod(); assert(mod >= 3 && mod % 2 == 1); auto tmp = mod - 1; max_base = 0; while(tmp % 2 == 0) tmp >>= 1, max_base++; root = 2; while(root.pow((mod - 1) >> 1) == 1) root += 1; assert(root.pow(mod - 1) == 1); dw.resize(max_base); idw.resize(max_base); for(int i = 0; i < max_base; i++) { dw[i] = -root.pow((mod - 1) >> (i + 2)); idw[i] = Mint(1) / dw[i]; } } void ntt(vector< Mint > &a) { const int n = (int) a.size(); assert((n & (n - 1)) == 0); assert(__builtin_ctz(n) <= max_base); for(int m = n; m >>= 1;) { Mint w = 1; for(int s = 0, k = 0; s < n; s += 2 * m) { for(int i = s, j = s + m; i < s + m; ++i, ++j) { auto x = a[i], y = a[j] * w; a[i] = x + y, a[j] = x - y; } w *= dw[__builtin_ctz(++k)]; } } } void intt(vector< Mint > &a, bool f = true) { const int n = (int) a.size(); assert((n & (n - 1)) == 0); assert(__builtin_ctz(n) <= max_base); for(int m = 1; m < n; m *= 2) { Mint w = 1; for(int s = 0, k = 0; s < n; s += 2 * m) { for(int i = s, j = s + m; i < s + m; ++i, ++j) { auto x = a[i], y = a[j]; a[i] = x + y, a[j] = (x - y) * w; } w *= idw[__builtin_ctz(++k)]; } } if(f) { Mint inv_sz = Mint(1) / n; for(int i = 0; i < n; i++) a[i] *= inv_sz; } } vector< Mint > multiply(vector< Mint > a, vector< Mint > b) { int need = a.size() + b.size() - 1; int nbase = 1; while((1 << nbase) < need) nbase++; int sz = 1 << nbase; a.resize(sz, 0); b.resize(sz, 0); ntt(a); ntt(b); Mint inv_sz = Mint(1) / sz; for(int i = 0; i < sz; i++) a[i] *= b[i] * inv_sz; intt(a, false); a.resize(need); return a; } }; int main() { int N; cin >> N; string S; cin >> S; NumberTheoreticTransformFriendlyModInt< modint > ntt; using E = Enumeration< modint >; vector< modint > C(N); { vector< modint > P(N), Q(N); for(int i = 0; i < N; i++) P[i] = (S[i] == 'i'); for(int i = 0; i < N; i++) Q[N - i - 1] = (S[i] == 'n'); auto R = ntt.multiply(P, Q); for(int i = 0; i + 1 < N; i++) C[i] = R[N - i - 2]; } { vector< modint > P(N + 1), Q(N + 1); for(int i = 0; i < N; i++) { P[i] = E::finv(i); Q[N - i] = C[i] * E::fact(i); } C = ntt.multiply(P, Q); } int ans = 0; for(int i = 0; i <= N - 2; i++) { ans ^= (C[N - i] * E::finv(i)).x; } cout << ans << "\n"; }