import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(2*10**5+10)
write = lambda x: sys.stdout.write(x+"\n")


n = int(input())
a = list(map(int, input().split()))
M = 998244353

### 素数の逆元とCombination

N = n+10 # 必要なテーブルサイズ
g1 = [0] * (N+1) # 元テーブル
g2 = [0] * (N+1) #逆元テーブル
inverse = [0] * (N+1) #逆元テーブル計算用テーブル
g1[0] = g1[1] = g2[0] = g2[1] = 1
inverse[0], inverse[1] = [0, 1] 
for i in range( 2, N + 1 ):
    g1[i] = ( g1[i-1] * i ) % M 
    inverse[i] = ( -inverse[M % i] * (M//i) ) % M # ai+b==0 mod M <=> i==-b*a^(-1) <=> i^(-1)==-b^(-1)*aより
    g2[i] = (g2[i-1] * inverse[i]) % M 
def cmb(n, r, M):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return ((g1[n] * g2[r] % M) * g2[n-r]) % M
def perm(n, r, M):
    if (r<0 or r>n):
        return 0
    return (g1[n] * g2[n-r]) % M
ans = 0
vs = [1]
v = 1
for i in range(N):
    v *= 2
    v %= M
    vs.append(v)
# ans = vs[n-1] * a[0]
for i in range(1,n+1):
    ans += a[i-1] * ((i-1) * vs[i-2] + vs[i-1]) * vs[n-i]
    ans %= M
print(ans)