#include <bits/stdc++.h>
#define N 3005

using namespace std;

const int mod = 998244353;

int n, S;
int a[N], f[N];

int main() {
	scanf("%d %d", &n, &S);
	for(int i = 1; i <= n; ++i)
		scanf("%d", &a[i]);
	
	int ans = 0;
	for(int i = 1; i <= n; ++i) {
		if(a[i] > S) continue;
		else if(a[i] == S) {
			ans = (ans + 1LL * i * (n - i + 1)) % mod;
		} else {
			ans = (ans + 1LL * f[S - a[i]] * (n - i + 1)) % mod;
			for(int j = S; j > a[i]; --j)
				(f[j] += f[j - a[i]]) %= mod;
			f[a[i]] = (f[a[i]] + i) % mod;
		}
	}
	
	printf("%d\n", ans);
	return 0;
}