N = int(input())
distance = list(map(int, input().split()))
price = list(map(int, input().split()))
min_price = 1000000000 # 기름을 넣을 가격(최소)
result = 0
for i in range(N-1):
tmp = price[i]
if min_price > tmp:
min_price = tmp
result += distance[i] * min_price
print(result)
알고리즘 문제
