n,s = list(map(int,input().split())); arr = list(map(int,input().split()))

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

for i in range(n):
    dp[0] += 1
    tmp = arr[i]
    for j in range(s,tmp-1,-1):
        dp[j] += dp[j-tmp]
        dp[j] %= mod
    ans += dp[s]
    ans %= mod
print(ans)