Problem:
Score : 200 points

Problem Statement

Takahashi went to an all-you-can-eat buffet with N kinds of dishes and ate all of them (Dish 1, Dish 2, \ldots, Dish N) once.

The i-th dish (1 \leq i \leq N) he ate was Dish A_i.

When he eats Dish i (1 \leq i \leq N), he gains B_i satisfaction points.

Additionally, when he eats Dish i+1 just after eating Dish i (1 \leq i \leq N - 1), he gains C_i more satisfaction points.

Find the sum of the satisfaction points he gained.

Constraints

All values in input are integers.

2 \leq N \leq 20

1 \leq A_i \leq N

A_1, A_2, ..., A_N are all different.

1 \leq B_i \leq 50

1 \leq C_i \leq 50

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N
B_1 B_2 ... B_N
C_1 C_2 ... C_{N-1}

Output

Print the sum of the satisfaction points Takahashi gained, as an integer.

Sample Input 1

3
3 1 2
2 5 4
3 6

Sample Output 1

14

Takahashi gained 14 satisfaction points in total, as follows:

First, he ate Dish 3 and gained 4 satisfaction points.

Next, he ate Dish 1 and gained 2 satisfaction points.

Lastly, he ate Dish 2 and gained 5 + 3 = 8 satisfaction points.

Sample Input 2

4
2 3 4 1
13 5 8 24
45 9 15

Sample Output 2

74

Sample Input 3

2
1 2
50 50
50

Sample Output 3

150

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#define REP(i, a, n) for(ll i=a; i<n; i++)
#define RREP(i, a, n) for(ll i=n-1; i>=a; i--)
typedef long long ll;
const ll mod =1e9+7;
const ll inf =1e18;
using namespace std;

int main() {
    ll n;
    ll a[21], b[21], c[21];
    cin>>n;
    REP(i, 0, n){
        cin>>a[i];
        a[i]--;
    }
    REP(i, 0, n) cin>>b[i];
    REP(i, 0, n-1) cin>>c[i];

    ll sum=b[a[0]];
    REP(i, 1, n){
        sum+=b[a[i]];
        if(a[i]-1 == a[i-1]){
            sum+=c[a[i-1]];
        }
    }
    cout<<sum<<endl;
    return 0;
}