def main():
    MOD = 998244353

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

if __name__ == '__main__':
    main()