MOD = 998244353

n, k = map(int, input().split())
A = list(map(int, input().split()))
if n == 1:
    print(A[0] * pow(2, k, MOD) % MOD)
    exit()

ave = sum(A) * pow(n, MOD - 2, MOD) % MOD
ans = ave * n * (pow(2, k, MOD) - 1) % MOD
print((ans + sum(A)) % MOD)