import sys
input = sys.stdin.readline

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

if K==0:
    print(sum(A)%MOD)
    exit()
    
MOD = 998244353
S = sum(A)*pow(N, K, MOD)

for Ai in A:
    S = (S+N*(pow(2, K, MOD)-1)*Ai*pow(N, K-1, MOD))%MOD

S = (S*pow(pow(N, K, MOD), MOD-2, MOD))%MOD
print(S)