#maspyさんのコード(https://yukicoder.me/submissions/602281)をもとにつくったO(NlogK)解

def check(N,K,A):
    import itertools
    MOD = 998_244_353
    def is_balanced(A, Acum):
        for a, b in zip(A[1:], Acum[1:]):
            if a > b:
                return False
        return True

    def main(N, K, A):
        S = [0] + list(itertools.accumulate(A))
        if not is_balanced(A, S):
            return 0

        res = 1

        for n in range(N-2,-1,-1):
            tmp = A[n] - 1 + S[n]
            flag = False
            for j in range(n+1,N):
                if tmp > K:
                    break
                if A[j]-1 >= tmp:
                    flag = True
                    break
                tmp *= 2
            if flag:
                res *= (A[n]+1+K)
                res %= MOD

        return res

    return main(N,K,A)

N,K = map(int,input().split())
A = list(map(int,input().split()))
print(check(N,K,A))