
n = int(input())

a = list(map(int, input().split()))

b = list(map(int, input().split()))

c = list(map(int, input().split()))

m = n-1
sumc = 0
for i in range(m):
    if a[i+1] == a[i]+1:
        sumc += c[i]
#tmp = a[m]
#if m > 1:
#    if tmp <= m:
#        sumc -= c[tmp-1]
#if m == 1:
#    if tmp == 1:
#        sumc = 0
ans = sum(b)
ans += sumc

print(ans)
