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

#include<cstdio>
#include<algorithm>
#define rg register
#define il inline
#define g getchar()
#define go(i,a,b) for(rg int i=a;i<=b;i++)
#define back(i,a,b) for(rg int i=a;i>=b;i--)
#define pf printf
using namespace std;
const int N=10002;
int n,m,a[N],b[N],c[N],ans;
bool vis[N];
il int fr(){
	int w=0,q=1;
	char ch=g;
	while(ch<'0'||ch>'9'){
		if(ch=='-') q=-1;
		ch=g;
	}
	while(ch>='0'&&ch<='9') w=(w<<1)+(w<<3)+ch-'0',ch=g;
	return w*q;
}
int main(){
	n=fr();m=fr();
	go(i,1,n) a[i]=fr();
	go(i,1,m) b[i]=fr();
	rg int k=0;
	go(i,0,m){
		if(vis[b[i]]) continue;
		while(b[i]==b[i-1]) i++;
		c[++k]=b[i];
		vis[b[i]]=1;
	}k--;
	go(i,1,k>>1) swap(c[i],c[k-i+1]);
	go(i,1,m){
		rg int s=0,j;
		for(j=k;j>=1;j--){
			if(b[i]==c[j]) break;
			s+=a[c[j]];
		}
		c[++k]=c[j];c[j]=0;ans+=s;
	}
	pf("%d\n",ans);
	return 0;
}