50 50
75 71 23 37 28 23 69 75 5 62 3 11 96 100 13 50 57 51 8 90 4 6 84 27 11 89 95 81 10 62 48 52 69 87 97 95 30 74 21 42 36 64 31 80 81 50 56 53 33 99
26 30 5 33 35 29 6 15 36 17 32 16 14 1 29 34 22 40 12 42 38 48 39 50 13 47 18 43 10 8 49 45 11 31 21 37 46 28 20 41 2 7 9 24 27 23 3 44 15 14
 10 10
61 59 97 16 2 94 57 48 91 93
2 8 6 5 3 1 3 4 9 10
 2 1
1 2
1
 3 3
10 20 30
1 2 3
 50 60
86 57 45 93 17 12 40 10 47 80 18 80 3 9 6 55 13 99 5 76 4 70 100 55 27 91 71 3 65 93 41 74 80 56 90 50 58 13 71 9 47 52 26 73 72 21 15 81 88 28
40 32 5 16 49 23 3 17 14 10 1 15 1 21 28 22 13 45 12 25 44 48 46 32 36 43 11 8 49 7 7 35 10 14 39 4 42 10 30 27 1 17 31 15 8 41 44 33 25 26 19 18 29 37 50 6 36 38 47 9
 2 7
20 30
1 1 1 2 2 2 2
 2 2
10 12
2 1
 5 1
16 87 36 16 81
3
 2 3
20 30
1 1 1
 2 10
39 26
1 1 2 2 2 2 2 2 1 2

63929
 2137
 0
 40
 62514
 20
 12
 0
 0
 104

import java.util.*;
import java.io.*;
public class A
{
      public static void main(String ar[]) throws Exception
      {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String s1[]=br.readLine().split(" ");
            int n=Integer.parseInt(s1[0]);
            int m=Integer.parseInt(s1[1]);
            
            String s2[]=br.readLine().split(" ");
            int a[]=new int[n];
            for(int i=0;i<n;i++)
             a[i]=Integer.parseInt(s2[i]);
            
            Stack<Integer> st=new Stack<Integer>();
            Stack<Integer> st1=new Stack<Integer>();
            HashSet<Integer> hs=new HashSet<Integer>();
            String s3[]=br.readLine().split(" ");
            int b[]=new int[m];
            for(int i=0;i<m;i++)
            {
                  int u=Integer.parseInt(s3[i]);
                  b[i]=u;
                  if(!hs.contains(u))
                  st.push(u);
                  hs.add(u);
            }
            
            while(!st.empty())
            {
                  st1.push(st.pop());
            }
            
            int S=0;
            for(int i=0;i<m;i++)
            {
                  while(!st1.empty() && st1.peek()!=b[i])
                  {
                        int u=st1.pop();
                        S+=a[u-1];
                        st.add(u);
                  }
                  
                  st1.pop();
                  while(!st.empty())
                  {
                  st1.push(st.pop());
                  }
                  
                  st1.push(b[i]);
            }
            
            System.out.println(S);
      }
}