N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
 
point = 0
for i in range(N):
    a[i] -= 1
    point += b[a[i]]
    if i > 0 and a[i - 1] + 1 == a[i]:
        point += c[a[i - 1]]
 
print(point)