def perferct_solve(N,K,A): mod = 998244353 diff = [A[0] for i in range(N)] S = A[0] for i in range(1,N): diff[i] = S - A[i] if diff[i] < 0: return 0 S += A[i] diff.append(0) sum_table = [0 for i in range(N)] sum_table[0] = diff[0] - diff[1] + 2*K + 1 for i in range(1,N): sum_table[i] = 2 * sum_table[i-1] + diff[i] - diff[i+1] - (2*K+1) dp = [[0 for minus in range(3*K+1)] for i in range(N)] for minus in range(3*K+1): dp_S = sum_table[0] - minus real_S = diff[1] + dp_S - 2*K - 1 first = diff[0] - minus if -K<=first<=K: dp[0][minus] = 1 if minus: dp[0][minus] += dp[0][minus-1] dp[0][minus] %= mod for i in range(1,N): sum = sum_table[i] for minus in range(3*K+1): dp_S = sum - minus real_S = dp_S + diff[i+1] - 2*K - 1 if diff[i]: L = max((real_S+minus+diff[i]+1)//2,-K+minus+diff[i]) R = min((real_S+minus+diff[i])//2,K+minus+diff[i]) if L==R: dp[i][minus] += dp[i-1][0] dp[i][minus] %= mod if minus%2==diff[i] and real_S%2==0 and -K<=real_S//2<=K: pre_minus_L = max(0,minus//2+1+diff[i]) pre_minus_R = min(3*K,minus//2+3*K+diff[i]) if pre_minus_L<=pre_minus_R: dp[i][minus] += dp[i-1][pre_minus_R] - dp[i-1][pre_minus_L-1] * (pre_minus_L>0) dp[i][minus] %= mod if diff[i]<=1 and (real_S+minus-diff[i])%2==0: m = max(0,-K+minus-diff[i]-(real_S+minus-diff[i])//2) M = min((minus-diff[i])//2,K+minus-diff[i]-(real_S+minus-diff[i])//2) pre_minus_L = max(0,m+diff[i]) pre_minus_R = min(3*K,M+diff[i]) if pre_minus_R>=pre_minus_L: dp[i][minus] += dp[i-1][pre_minus_R] - dp[i-1][pre_minus_L-1] * (pre_minus_L>0) dp[i][minus] %= mod if minus: dp[i][minus] += dp[i][minus-1] dp[i][minus] %= mod return dp[N-1][0] N,K = map(int,input().split()) A = list(map(int,input().split())) print(perferct_solve(N,K,A))