N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=list(map(int,input().split()))

P=0
P+=B[A[0]-1]
for i in range(N-1):
    if A[i]!=N and A[i+1]!=1:
        u=B[A[i+1]-1]
        q=C[A[i+1]-2]
        o=u+q
        P+=o
    elif A[i]!=N and A[i+1]==1:
        u=B[A[i+1]-1]
        P+u
    else:
        u=B[A[i+1]-1]
        P+=u
    
print(int(P))