MOD = 998244353

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

DP = [[[0] * 3 for _ in range(S + 1)] for _ in range(N + 1)]
DP[0][0][0] = 1

for i in range(N):
    DP[i + 1][0][0] = DP[i][0][0] 
    DP[i + 1][0][1] = DP[i][0][0] + DP[i][0][1]
    a = A[i]
    if a > S:
        for j in range(1, S + 1):
            DP[i + 1][j][1] = (DP[i][j][0] + DP[i][j][1]) % MOD #以前から合計jになっている場合のみOK
    else:
        for j in range(1, a):
            DP[i + 1][j][1] = (DP[i][j][0] + DP[i][j][1]) % MOD #以前から合計jになっている場合のみOK
        for j in range(a, S + 1):
            DP[i + 1][j][1] = (DP[i][j][0] + DP[i][j][1] + DP[i][j - a][0] + DP[i][j - a][1]) % MOD

    DP[i + 1][S][2] = (DP[i][S][1] + DP[i][S][2]) % MOD
    if a <= S:
        DP[i + 1][S][2] += DP[i][S - a][0] + DP[i][S - a][1]
    DP[i + 1][S][2] %= MOD

print (DP[N][S][2])

# for i in range(N + 1):
#     print (DP[i])