#include <bits/stdc++.h>
using namespace std;
template <typename Arg1, typename Arg2>
ostream& operator<<(ostream& out, const pair<Arg1, Arg2>& x) {
  return out << "(" << x.first << "," << x.second << ")";
}
template <typename Arg1>
ostream& operator<<(ostream& out, const vector<Arg1>& a) {
  out << "[";
  for (const auto& x : a) out << x << ",";
  return out << "]";
}
template <typename Arg1>
ostream& operator<<(ostream& out, const set<Arg1>& a) {
  out << "[";
  for (const auto& x : a) out << x << ",";
  return out << "]";
}
template <typename Arg1, typename Arg2>
ostream& operator<<(ostream& out, const map<Arg1, Arg2>& a) {
  out << "[";
  for (const auto& x : a) out << x << ",";
  return out << "]";
}
template <typename Arg1>
void __trace__(const string name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << " ] " << endl;
}
template <typename Arg1, typename... Args>
void __trace__(const string names, Arg1&& arg1, Args&&... args) {
  const string name = names.substr(0, names.find(','));
  cerr << name << " : " << arg1 << " | ";
  __trace__(names.substr(1 + (int)name.size()), args...);
}
clock_t time_p = clock();
void time_taken() {
  time_p = clock() - time_p;
  cerr << "Time Taken : " << (float)(time_p) / CLOCKS_PER_SEC << "\n";
}
const long long mod = 998244353;
const long long INF = 1e18;
long long modinv(long long a, long long m) {
  assert(m > 0);
  if (m == 1) return 0;
  a %= m;
  if (a < 0) a += m;
  assert(a != 0);
  if (a == 1) return 1;
  return m - modinv(m, a) * m / a;
}
template <int MOD_>
struct modnum {
 private:
  int v;

 public:
  static const int MOD = MOD_;
  modnum() : v(0) {}
  modnum(long long v_) : v(int(v_ % MOD)) {
    if (v < 0) v += MOD;
  }
  explicit operator int() const { return v; }
  friend bool operator==(const modnum& a, const modnum& b) {
    return a.v == b.v;
  }
  friend bool operator!=(const modnum& a, const modnum& b) {
    return a.v != b.v;
  }
  modnum operator~() const {
    modnum res;
    res.v = modinv(v, MOD);
    return res;
  }
  modnum& operator+=(const modnum& o) {
    v += o.v;
    if (v >= MOD) v -= MOD;
    return *this;
  }
  modnum& operator-=(const modnum& o) {
    v -= o.v;
    if (v < 0) v += MOD;
    return *this;
  }
  modnum& operator*=(const modnum& o) {
    v = int(long long(v) * long long(o.v) % MOD);
    return *this;
  }
  modnum& operator/=(const modnum& o) { return *this *= (~o); }
  friend modnum operator+(const modnum& a, const modnum& b) {
    return modnum(a) += b;
  }
  friend modnum operator-(const modnum& a, const modnum& b) {
    return modnum(a) -= b;
  }
  friend modnum operator*(const modnum& a, const modnum& b) {
    return modnum(a) *= b;
  }
  friend modnum operator/(const modnum& a, const modnum& b) {
    return modnum(a) /= b;
  }
};
using num = modnum<mod>;
vector<num> fact;
vector<num> ifact;
void init() {
  fact = {1};
  for (int i = 1; i < 100000; i++) fact.push_back(i * fact[i - 1]);
  for (num x : fact) ifact.push_back(1 / x);
}
num ncr(int n, int k) {
  if (k < 0 || k > n) return 0;
  return fact[n] * ifact[k] * ifact[n - k];
}
num powmod(num x, int a) {
  if (a == 0) return 1;
  if (a & 1) return x * powmod(x, a - 1);
  return powmod(x * x, a / 2);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cout.precision(12);
  cout << fixed;
  int n;
  cin >> n;
  int s;
  cin >> s;
  vector<int> a(n);
  for (int i = 0; i < n; i++) cin >> a[i];
  num ans = 0;
  vector<vector<num>> dp(n + 1, vector<num>(s + 1));
  vector<num> sum(s + 1);
  for (int i = n - 1; i >= 0; i--) {
    dp[i][a[i]] = (n - i);
    for (int j = a[i] + 1; j <= s; j++) {
      dp[i][j] += sum[j - a[i]];
    }
    for (int j = 0; j < s + 1; j++) {
      sum[j] += dp[i][j];
    }
    ans += dp[i][s] * (i + 1);
  }
  cout << int(ans) << '\n';
  time_taken();
  return 0;
}
