N = int(input())
A = list(map(int,input().split()))
mod = 998244353
n = len(set(A))
ans = 0
cumJ = 0
cumI = 0
ope = lambda x,y:(x+y) % mod
for i in range(N):
    ans -=(cumJ * pow(2,N-1-i))%mod * A[i]
    ans %=mod
    '''
    ans += segJ.sum(0,zipped[i]) * pow(2,N-1-i) * A[i]
    ans %=mod
    '''
    cumJ += pow(2,i,mod)
    cumJ %=mod
rev2 = pow(2,mod-2,mod)
cumI = [0] * N
cumI[0] = 1
for i in range(1,N):
    cumI[i] = cumI[i-1] * rev2
    cumI[i] %=mod
def acum(List):#累積和
    rev = [0 for _ in range(len(List))]
    for i in range(len(List)):
        if i == 0:
            rev[i] = List[i]
        else:
           rev[i] = rev[i-1] + List[i] 
    return rev
cumI = acum(cumI)
for i in reversed(range(N)):
    '''

    ans -= segI.sum(zipped[i]+1,n) * pow(2,N-1+i) * A[i]
    ans %=mod
    '''
    ans += (cumI[N-1]-cumI[i]) * pow(2,N-1+i) % mod * A[i]
    ans %=mod
print(ans)