n = int(input())
a = list(map(int,input().split()))
b = list(map(int,input().split()))
c = list(map(int,input().split()))
sum_satisfaction = sum(b)

for i in range(0,n-1):
    if(i < n-2 and a[i+1] == a[i] + 1 ):
        sum_satisfaction = sum_satisfaction + c[i+1]
    elif(i >= n-2 and a[i+1] == a[i] + 1 ):
        sum_satisfaction = sum_satisfaction + c[i-1]
print(sum_satisfaction)