#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 { 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 >(); int main() { int N, M; cin >> N >> M; vector< int > P(N); cin >> P; for(auto &p : P) --p; vector< int > used(N), beet; for(int i = 0; i < N; i++) { if(!used[i]) { int now = i, len = 0; while(!used[now]) { used[now] = true; ++len; now = P[now]; } beet.emplace_back(len); } } modint ret = 0; Enumeration< modint > tap; for(int i = 2; i <= M; i++) { modint mul = 1; for(auto &len : beet) { mul *= modint(i - 1).pow(len) + modint((len & 1) ? -1 : 1) * (i - 1); } ret += mul * tap.C(M, i) * (((M ^ i) & 1) ? -1 : 1); } cout << ret * tap.finv(M) << "\n"; }