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.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;

public class CF_GOODBYE2014_C {
    
    static Reader sc = new Reader();
    static PrintWriter out = new PrintWriter(System.out); 
    
    public static void main(String[] args) throws IOException {
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        int[] w = sc.na(n);
        int[] ord = sc.na(m);
        
        boolean[] put = new boolean[n];
        
        int ind = 0;
        ArrayList<Integer> res = new ArrayList<Integer>();
        
        for (int i = 0; i < m; i++) {
            if(!put[ord[i]-1]) {
                res.add(ord[i]);
                put[ord[i]-1] = true;
            }
        }
        
        int cost = 0;
        for (int i = 0; i < m; i++) {
            int currCost = 0;
            for (int act : res) {
                if(act != ord[i]) {
                    currCost += w[act-1];
                } else {
                    cost += currCost;
                    res.remove((Integer)ord[i]);
                    res.add(0, ord[i]);
                    break;
                }
            }           
        }
                
        out.println(cost);
        out.close();
    }
    
    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;private byte[] buffer;private int bufferPointer, bytesRead;
        public Reader(){buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;
        }private void fillBuffer() throws IOException{bytesRead=System.in.read(buffer,bufferPointer=0,BUFFER_SIZE);if(bytesRead==-1)buffer[0]=-1;
        }private byte read() throws IOException{if(bufferPointer==bytesRead)fillBuffer();return buffer[bufferPointer++];
        }public String next() throws IOException{StringBuilder sb = new StringBuilder();byte c;while((c=read())<=' '){if(c==-1) return null;};do{sb.append((char)c);}while((c=read())>' ');if (sb.length()==0) return null;return sb.toString();
        }public String nextLine() throws IOException{StringBuilder sb = new StringBuilder();byte c;boolean read = false;while((c=read())!=-1){if(c=='\n') {read = true;break;}if(c>=' ')sb.append((char)c);}if (!read) return null;return sb.toString();
        }public int nextInt() throws IOException{int ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;
        }public long nextLong() throws IOException{long ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c=read();do{ret=ret*10L+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;
        }public double nextDouble() throws IOException{double ret=0,div=1;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c = read();do {ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(c=='.')while((c=read())>='0'&&c<='9')ret+=(c-'0')/(div*=10);if(neg)return -ret;return ret;
        }public int[] na(int n) throws IOException{int[] a = new int[n];for(int i = 0;i < n;i++)a[i] = nextInt();return a;
        }public int[][] nm(int n, int m) throws IOException{int[][] map = new int[n][m];for(int i = 0;i < n;i++)map[i] = na(m);return map;
        }public void close() throws IOException{if(System.in==null) return;System.in.close();}
    }
    
    static void print(int[] A) {for(int i=0;i<A.length;i++){if(i!=0) out.print(' ');out.print(A[i]);}out.println();}
    static <T> void print(Iterable<T> A) {int i = 0;for(T act : A){if(i!=0)out.print(' ');out.print(act);i++;}out.println();}
    static void printPlus1(Iterable<Number> A) {int i = 0;for(Number act : A){if(i!=0)out.print(' ');out.print(act.longValue() + 1L);i++;}out.println();}
    static void debug(Object... o) { System.err.println(Arrays.deepToString(o)); }
    
    /*
    long s = System.currentTimeMillis();
    debug(System.currentTimeMillis()-s+"ms");
     */
}
