#B140 
n  = int(input())
a  = list(map(int , input().split()))
b  =list(map(int , input().split()))
c  = list(map(int , input().split()))

get_point = sum(b)
for i in range(n-1):
    if a[i] + 1 == a[i + 1] :
        get_point = get_point + c[i]
    else:
        get_point = get_point
    
        
print(get_point)