n = 0
a = []
b = []
c = []

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

sum = 0
tmp = 0
cc = 0

for m in range(n):
    i = a[m]
    if tmp == i-1:
        cc = c[i-2]
    else:
        cc = 0
    sum += b[i-1]
    sum += cc
    tmp = i

print(sum)
