n = int(input())

a = [int(i) for i in input().split()]
b = [int(i) for i in input().split()]
c = [int(i) for i in input().split()]

ans = sum(b)
for i in range(len(a)-1):
    if a[i]+1 == a[i+1]:
        ans += c[a[i]-1]


print(ans)
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