n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
c=list(map(int,input().split()))
co=0
for i in range(n):
    co=co+b[i]
for i in range(n-1):
    if a[i]+1==a[i+1]:
        co+=c[a[i]-1]

print(co