#include <bits/stdc++.h>
using namespace std;
int main() {
  const size_t M = 998244353;
  size_t N, S;
  cin >> N >> S;
  vector<size_t> a(N);
  for (auto& x : a) {
    cin >> x;
  }
  size_t res = 0;
  vector<size_t> dp(S + 1, 0);
  for (size_t i = 0; i < N; ++i) {
    dp[0] += 1;
    for (int s = S; s >= 0; --s) {
      if (a[i] + s <= S) {
        dp[a[i] + s] += dp[s] % M;
      }
    }
    res += dp[S] % M;
  }
  cout << res;
  return 0;
}
