n = int(input())
a = list(map(int,input().split(" ")))
b = list(map(int,input().split(" ")))
c = list(map(int,input().split(" ")))
m,j = [0,0]
for i in a:
    m += b[i-1]
    if i == j + 1:
        m += c[i-2]
    j = i
print(m)