N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))

ans = 0

for i in range(1, N+1):
    a = A[i-1]
    ans += B[a-1]
    
for j in range(N-1):
    if A[j] == A[j-1]+1:
        ans += C[j]

print(ans)