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.math.BigInteger;
import java.util.*;


public class A
{
        String line;
        StringTokenizer inputParser;
        BufferedReader is;
        FileInputStream fstream;
        DataInputStream in;
        String FInput="";
        
        void openInput(String file)
        {
            if(file==null)is = new BufferedReader(new InputStreamReader(System.in));//stdin
            else
            {
                    try{
            
                            
                    fstream = new FileInputStream(file);
                    in = new DataInputStream(fstream);
                    is = new BufferedReader(new InputStreamReader(in));
                    }catch(Exception e)
                    {
                            System.err.println(e);
                    }
            }
        }
        
        void readNextLine()
    	{
    		try {
    			line = is.readLine();
    			inputParser = new StringTokenizer(line, " ,\t");
    			//System.err.println("Input: " + line);
    		} catch (IOException e) {
    			System.err.println("Unexpected IO ERROR: " + e);
    		}	
    		catch (NullPointerException e)
    		{
    			line=null;
    			
    		}
    		
    	}
        
        long NextLong()
        {
                String n = inputParser.nextToken();
                
                long val = Long.parseLong(n);
                
                 return val;
        }
        
        int NextInt()
        {
                String n = inputParser.nextToken();
                int val = Integer.parseInt(n);
                
                //System.out.println("I read this number: " + val);
                return val;
        }
        
        double NextDouble()
        {
                String n = inputParser.nextToken();
                double val = Double.parseDouble(n);
                
                //System.out.println("I read this number: " + val);
                return val;
        }
        
        String NextString()
        {
                String n = inputParser.nextToken();
                return n;
        }
        
        void closeInput()
        {
                try {
                        is.close();
                } catch (IOException e) {
                        System.err.println("Unexpected IO ERROR: " + e);
                }
                        
        }
        
        
        public static void main(String [] argv)
        {
                //String filePath="circles.in";
                String filePath=null;
                if(argv.length>0)filePath=argv[0];
                new A(filePath);
                
        }
        
        public A(String inputFile)
        {
        	Random rgen = new Random();
        	openInput(inputFile);
    		//readNextLine();
    		int n=1;//NextInt();
    		for(int t=0; t<n; t++)
    		{
    			readNextLine();
    			int N=NextInt();
    			int M=NextInt();
    			int [] p = new int[M];
    			int [] w = new int[N];
    			readNextLine();
    			for(int i=0; i<N; i++)
    			{
    				w[i] = NextInt();
    			}
    			readNextLine();
    			for(int i=0; i<M; i++)
    			{
    				p[i] = NextInt();
    			}
    			Stack <Integer> st = new Stack<Integer>();
    			Stack <Integer> tmp = new Stack<Integer>();
    			for(int i=0; i<M; i++)
    			{
    				if(!st.contains(p[i]))tmp.push(p[i]);
    			}
    			while(!tmp.isEmpty())
					st.push(tmp.pop());
    			int ret = 0;
    			for(int i=0; i<M; i++)
    			{
    				int now = 0;
    				
    				while(st.peek()!=p[i])
    				{
    					tmp.push(st.pop());
    					now+=w[tmp.peek()-1];
    				}
    				int read = st.pop();
    				while(!tmp.isEmpty())
    					st.push(tmp.pop());
    				st.push(read);
    				
    				ret += now;
    			}
    			System.out.println(ret);
    		}
    		
    		
    		closeInput();		
      
        }


       
}