n = int(input())
a_s = list(map(int, input().split(' ')))
b_s = list(map(int, input().split(' ')))
c_s = list(map(int, input().split(' ')))

sat = 0
for i in range(0, n):
    idx = a_s[i] - 1
    b = b_s[idx]
    sat += b
    if i < n-1 and a_s[i] +1 == a_s[i+1]:
        if i > 0:
            sat += c_s[i-1]
print(sat)