N,S = map(int,input().split())
 
A = list(map(int,input().split()))

dp = [0] * (S+1)
ans = 0
mod = 998244353


for i in range(N):
 
    ndp = []
    for ll in dp:
        ndp.append(ll)
 
    if A[i] <= S:
        ndp[A[i]] += i+1
        ndp[A[i]] %= mod
 
    for j in range(S):
        if j+A[i] <= S:
            ndp[j+A[i]] += dp[j]
            ndp[j+A[i]] %= mod
 
    ans += ndp[S]
    ans %= mod
 
    dp = ndp

print(ans)
