N=int(input())
A=list(map(int,input().split()))
p=998244353

def exp(a,b,p):
    ans,mul,div=1,a,1
    for i in range(70):
        if b//div%2==1:
            ans*=mul
            ans%=p
        mul=mul**2%p
        div*=2
    return ans%p


left=[1]
l=0
for i in range(1,N+10):
    left.append((1+i*exp(2,i-1,p)+exp(2,i,p)-1)%p)
    l=left[-1]
ans=0
for i in range(N):
    ans+=A[i]*left[i]*left[N-1-i]%p
print(ans)