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.io.*;
import java.util.*;
import static java.lang.Math.*;
 public class Sample

{
     BufferedReader read;
     BufferedWriter write;
    public static void main(String args[]) throws Exception
    {
        new Sample().init("1");
    }
    int wt[],order[];
    ArrayList<Integer>ls;
     void init(String name) throws Exception
    {
        read= ri();//rf(name+".txt");
      int p[]=ia(read.readLine());
      int n=p[0];
      int m=p[1];
     wt=ia(read.readLine());
     order=ia(read.readLine());
     for(int i=0;i<m;i++)order[i]--;
     ls=new ArrayList<Integer>();
     boolean done[]=new boolean[n];
     
     for(int i:order)if(!done[i])
    	 {
    	 ls.add(i);
    	 done[i]=true;
    	 }
    
     long ans=0;
     for(int i:order)ans+=get(i);
     System.out.println(ans);
        read.close();
    }
int get(int in)
{
	int sum=0;
	int sz=ls.size();
	for(int i=0;i<sz;i++)
	{
		int t=ls.get(i);
		if(t==in)
			{
			ls.remove(i);
			ls.add(0,in);
			break;
			}
		else sum+=wt[t];
	}
	
	return sum;
}
void result(int ppp) throws Exception
{
  
}
boolean isPalindrome(long l)
{
   char c[]=(""+l).toCharArray();
   for(int i=0;i<c.length;i++)if(c[i]!=c[c.length-i-1])return false;
   return true;
}
int i(String s){return Integer.parseInt(s.trim());}
long l(String s){return Long.parseLong(s.trim());}
double d(String s){return Double.parseDouble(s.trim());}
 int[] ia(String s1){String s[]=s1.trim().split(" ");int p[]=new int[s.length];for(int i=0;i<s.length;i++)p[i]=Integer.parseInt(s[i]);return p;}
 long[] la(String s)
 {
     String s1[]=s.split(" ");
     long la[]=new long[s1.length];
     for(int i=0;i<s1.length;i++)la[i]=l(s1[i]);
     return la;
 }
 double [] ld(String s)
  {
    String s1[]=s.split(" ");
    int l=s1.length;
   double d[]=new double[l];
   for(int i=0;i<l;i++)d[i]=d(s1[i]);
   return d;
 }
static BufferedWriter wf(String s) throws Exception{return new BufferedWriter(new FileWriter(new File(s)));}
static BufferedReader rf(String s) throws Exception{return new BufferedReader(new FileReader(new File(s)));}
static BufferedReader ri() throws Exception{return new BufferedReader(new InputStreamReader(System.in));}
boolean st(int i,long num)
{
   return  ((num>>i)&1)!=0;
}


}

