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


s = 0
for i in xrange(n-1):
    s+= b[a[i]-1]
    
    if a[i] +1 == a[i+1]:
        
        s+= c[a[i]-1]
print s+b[a[-1]-1]