Given are a sequence of $N$ integers $A_1, A_2, \ldots, A_N$ and a positive integer $S$.
For a pair of integers $(L,R)$ such that $1 \le L \le R \le N$, let us define $f(L,R)$ as follows:
Find the sum of $f(L,R)$ over all pairs of integers $(L,R)$ such that $1 \le L \le R \le N$. Since this sum can be enormous, print it modulo $998244353$.
The first line contains two integers $N$, $S$.
The second line contains $N$ integers $A_1, A_2, \ldots, A_N$.
$1 \le N, S, A_i \le 3000$.
Print the sum of $f(L,R)$, modulo $998244353$.
For the first example:
The value of $f(L,R)$ for each pair is as follows, for a total of $5$.
$f(1,1)=0$
$f(1,2)=1$ (for the sequence $(1,2)$)
$f(1,3)=2$ (for $(1,2)$ and $(3)$)
$f(2,2)=0$
$f(2,3)=1$ (for $(3)$)
$f(3,3)=1$ (for $(3)$)