day = int(input())
money = 0
a = list(map(int, input().split()))
for i in range(day):
cost = cost + (i+1)*a[ i ]
day = int(input()) money = 0 a = list(map(int, input().split())) for i in range(day): cost = cost + (i+1)*a[ i ]
好了啦李聖恩沒打完 去打地鼠啦 看看香山高中的威力