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.*;
public final class GFG {
  
	public static void main (String[] args) {
	//	System.out.println("GfG!");
	Scanner scan=new Scanner(System.in);
	int n=scan.nextInt();
	int m=scan.nextInt();
	int[] b=new int[n];
	int[] a=new int[m];
	for(int i=0;i<n;i++)
	   b[i]=scan.nextInt();
	   	
	   	for(int i=0;i<m;i++)
	   a[i]=scan.nextInt();
	   int sum=0;
Stack<Integer> s1 = new Stack<Integer>();	   
Stack<Integer> s = new Stack<Integer>();
Stack<Integer> s2 = new Stack<Integer>();
	for(int i=0;i<m;i++)
	{ Integer pos = (Integer) s2.search(a[i]);
	    if(pos==-1)
	    s2.push(a[i]);
	   
	}
//System.out.println(s2);	
for(int i=0;i<n&&(!s2.empty());i++)
{
   int c= s2.pop();
    s.push(c);
}

//System.out.println(s);
	//	reverse(s);
	for(int i=0;i<m;i++)
	{Integer pos1 = (Integer) s.search(a[i]);
	//	System.out.println(pos1+" "+a[i]);
	  
	  
	      for(int j=0;j<pos1-1;j++)
	      {  int a1=s.pop();
	          sum=sum+b[a1-1];
	          s1.push(a1);
	          //	System.out.println("sum"+sum);
	      }
	      

s.pop();
for(int j=0;j<pos1-1;j++)
	      {  int a1=s1.pop();
	          //sum=sum+a;
	          s.push(a1);
	      }
	      s.push(a[i]);
	  
	}
	System.out.println(sum);
	}
}