from itertools import combinations
n=int(input())
a=list(map(int,input().split()))
point=0

def score(l):
    score=0
    for i in range(len(l)):
        score+=l[i]*(i+1)
    return score

for i in range(1,n+1):
    m=list(combinations(range(n),i))
    for j in m:
        p=[]
        for k in range(len(j)):
            p.append(a[j[k]])   
        point+=score(p)
print(point%998244353)
print()