/* Aa^~ kokoro ga pyonpyon suru n jaa^~
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*/
#include<bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x...) do { cout << "\033[32;1m " << #x << " -> "; err(x); } while (0)
void err() { cout << "\033[39;0m" << endl; }
template<template<typename...> class T, typename t, typename... A>
void err(T<t> a, A... x) { for (auto v: a) cout << v << ' '; err(x...); }
template<typename T, typename... A>
void err(T a, A... x) { cout << a << ' '; err(x...); }
#else
#define dbg(...)
#endif
typedef long long ll;
typedef pair<int,int> pi;
typedef vector<int> vi;
template<class T> using vc=vector<T>;
template<class T> using vvc=vc<vc<T>>;
template<class T> void mkuni(vector<T>&v)
{
    sort(v.begin(),v.end());
    v.erase(unique(v.begin(),v.end()),v.end());
}
ll rand_int(ll l, ll r) //[l, r]
{
    static mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count());
    return uniform_int_distribution<ll>(l, r)(gen);
}
template<class T>
void print(T x,int suc=1)
{
    cout<<x;
    if(suc==1) cout<<'\n';
    else cout<<' ';
}
template<class T>
void print(const vector<T>&v,int suc=1)
{
    for(int i=0;i<v.size();i++)
    print(v[i],i==(int)(v.size())-1?suc:2);
}
const int mod=998244353;
const int maxn=3005;
int dp[maxn];
int main()
{
    int n,s;
    cin>>n>>s;
    vi a(n);
    for(int i=0;i<n;i++) cin>>a[i];
    ll ans=0;
    for(int i=0;i<n;i++)
    {
        if(a[i]<s)
            ans=(ans+(ll)dp[s-a[i]]*(n-i)%mod)%mod;
        else if(a[i]==s)
            ans=(ans+(ll)(i+1)*(n-i)%mod)%mod;
        for(int j=s;j>a[i];j--)
            dp[j]=(dp[j]+dp[j-a[i]])%mod;
        dp[a[i]]=(dp[a[i]]+i+1)%mod;
    }
    print(ans);
}

Measured memory_bytes: 256