#include using namespace std; typedef long long ll; #define pb(x) push_back(x) #define mp(a, b) make_pair(a, b) #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define lscan(x) scanf("%I64d", &x) #define lprint(x) printf("%I64d", x) #define rep(i, n) for (ll i = 0; i < (n); i++) #define rep2(i, n) for (ll i = (ll)n - 1; i >= 0; i--) #define REP(i, l, r) for (ll i = l; i < (r); i++) #define REP2(i, l, r) for (ll i = (ll)r - 1; i >= (l); i--) #define siz(x) (ll)x.size() template using rque = priority_queue, greater>; const ll mod = 998244353; template bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; } template bool chmax(T &a, const T &b) { if (b > a) { a = b; return 1; } return 0; } ll gcd(ll a, ll b) { if(a == 0) return b; if(b == 0) return a; ll cnt = a % b; while (cnt != 0) { a = b; b = cnt; cnt = a % b; } return b; } long long extGCD(long long a, long long b, long long &x, long long &y) { if (b == 0) { x = 1; y = 0; return a; } long long d = extGCD(b, a % b, y, x); y -= a / b * x; return d; } struct UnionFind { vector data; int num; UnionFind(int sz) { data.assign(sz, -1); num = sz; } bool unite(int x, int y) { x = find(x), y = find(y); if (x == y) return (false); if (data[x] > data[y]) swap(x, y); data[x] += data[y]; data[y] = x; num--; return (true); } int find(int k) { if (data[k] < 0) return (k); return (data[k] = find(data[k])); } ll size(int k) { return (-data[find(k)]); } bool same(int x, int y){ return find(x) == find(y); } }; ll M = 1000000007; template 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(t); return (is); } static int get_mod() { return mod; } }; using mint = ModInt; mint mpow(mint x, ll n) { mint ans = 1; while (n != 0) { if (n & 1) ans *= x; x *= x; n = n >> 1; } return ans; } ll mpow2(ll x, ll n, ll mod) { ll ans = 1; while (n != 0) { if (n & 1) ans = ans * x % mod; x = x * x % mod; n = n >> 1; } return ans; } vector fac; vector ifac; void setcomb(int sz = 2000010) { fac.assign(sz + 1, 0); ifac.assign(sz + 1, 0); fac[0] = 1; for (ll i = 0; i < sz; i++) { fac[i + 1] = fac[i] * (i + 1); // n!(mod M) } ifac[sz] = fac[sz].inverse(); for (ll i = sz; i > 0; i--) { ifac[i - 1] = ifac[i] * i; } } mint comb(ll a, ll b) { if(fac.size() == 0) setcomb(); if (a == 0 && b == 0) return 1; if (a < b || a < 0 || b < 0) return 0; return ifac[a - b] * ifac[b] * fac[a]; } mint perm(ll a, ll b) { if(fac.size() == 0) setcomb(); if (a == 0 && b == 0) return 1; if (a < b || a < 0) return 0; return fac[a] * ifac[a - b]; } long long modinv(long long a) { long long b = M, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= M; if (u < 0) u += M; return u; } ll modinv2(ll a, ll mod) { ll b = mod, u = 1, v = 0; while (b) { ll t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= mod; if (u < 0) u += mod; return u; } template struct NumberTheoreticTransform { vector rev, rts; int base, max_base, root; NumberTheoreticTransform() : base(1), rev{0, 1}, rts{0, 1} { assert(mod >= 3 && mod % 2 == 1); auto tmp = mod - 1; max_base = 0; while (tmp % 2 == 0) tmp >>= 1, max_base++; root = 2; while (mod_pow(root, (mod - 1) >> 1) == 1) ++root; assert(mod_pow(root, mod - 1) == 1); root = mod_pow(root, (mod - 1) >> max_base); } inline int mod_pow(int x, int n) { int ret = 1; while (n > 0) { if (n & 1) ret = mul(ret, x); x = mul(x, x); n >>= 1; } return ret; } inline int inverse(int x) { return mod_pow(x, mod - 2); } inline unsigned add(unsigned x, unsigned y) { x += y; if (x >= mod) x -= mod; return x; } inline unsigned mul(unsigned a, unsigned b) { return 1ull * a * b % (unsigned long long)mod; } void ensure_base(int nbase) { if (nbase <= base) return; rev.resize(1 << nbase); rts.resize(1 << nbase); for (int i = 0; i < (1 << nbase); i++) { rev[i] = (rev[i >> 1] >> 1) + ((i & 1) << (nbase - 1)); } assert(nbase <= max_base); while (base < nbase) { int z = mod_pow(root, 1 << (max_base - 1 - base)); for (int i = 1 << (base - 1); i < (1 << base); i++) { rts[i << 1] = rts[i]; rts[(i << 1) + 1] = mul(rts[i], z); } ++base; } } void ntt(vector &a) { const int n = (int)a.size(); assert((n & (n - 1)) == 0); int zeros = __builtin_ctz(n); ensure_base(zeros); int shift = base - zeros; for (int i = 0; i < n; i++) { if (i < (rev[i] >> shift)) { swap(a[i], a[rev[i] >> shift]); } } for (int k = 1; k < n; k <<= 1) { for (int i = 0; i < n; i += 2 * k) { for (int j = 0; j < k; j++) { mint z = a[i + j + k] * rts[j + k]; a[i + j + k] = a[i + j] - z; a[i + j] = a[i + j] + z; } } } } vector multiply(vector a, vector b) { int need = a.size() + b.size() - 1; int nbase = 1; while ((1 << nbase) < need) nbase++; ensure_base(nbase); int sz = 1 << nbase; a.resize(sz, 0); b.resize(sz, 0); ntt(a); ntt(b); mint inv_sz = inverse(sz); for (int i = 0; i < sz; i++) { a[i] = a[i] * b[i] * inv_sz; } reverse(a.begin() + 1, a.end()); ntt(a); a.resize(need); return a; } }; using NTT = NumberTheoreticTransform; int main(){ ios::sync_with_stdio(false); std::cin.tie(nullptr); ll n, k; cin >> n >> k; ll a[n]; rep(i, n) cin >> a[i]; map cnt; rep(i, n) cnt[a[i]]++; mint dp[n + 1][k + 1][n + 1] = {}; rep(t, n + 1) dp[0][0][t] = 1; REP(i,1,n+1)rep(j,k+1)rep(t,n+1){ if(j == 0){ dp[i][j][t] = 1; continue; } if(t == 0) continue; dp[i][j][t] = dp[i][j][t - 1]; if(j >= t) dp[i][j][t] += dp[i - 1][j - t][t]; } NTT ntt; vector d(1, 1); ll sum = 0; for(auto e: cnt){ ll ncnt = e.second; vector nd(min(k, sum * ncnt) + 1); rep(i, nd.size()) nd[i] = dp[ncnt][i][sum]; d = ntt.multiply(d, nd); sum += ncnt; } cout << d[k] << endl; }