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

mod=998244353

FACT=[1]
for i in range(1,2*10**5+1):
    FACT.append(FACT[-1]*i%mod)

FACT_INV=[pow(FACT[-1],mod-2,mod)]
for i in range(2*10**5,0,-1):
    FACT_INV.append(FACT_INV[-1]*i%mod)

FACT_INV.reverse()

def Combi(a,b):
    if 0<=b<=a:
        return FACT[a]*FACT_INV[b]%mod*FACT_INV[a-b]%mod
    else:
        return 0

score=0

k=N-1

for i in range(k+1):
    score=(score+(i+1)*Combi(k,i))%mod

X=pow(2,k-1,mod)
INV=pow(2,mod-2,mod)

ANS=score*A[-1]%mod

#print(ANS)
now=2
for i in range(N-1):
    ANS=(ANS+now*X*A[i]*INV)%mod
    #print(now*X*INV%mod)
    now+=1


print(ANS%mod)