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 <set>
#include <map>
#include <ctime>
#include <queue>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#warning ORZAKF

using namespace std;

#ifdef Paladin
	#define DeBug(_MDL_...) printf(_MDL_)
#else
	#define DeBug(_MDL_...)
#endif

#ifdef WIN32
	#define LL "%I64d"
#else
	#define LL "%lld"
#endif

#define Mdl_Cmax(x, y) ((x) < (y) ? (x) = (y) : 0)
#define Mdl_Cmin(x, y) ((x) > (y) ? (x) = (y) : 0)
#define Mdl_Max(x, y) ((x) > (y) ? (x) : (y))
#define Mdl_Min(x, y) ((x) < (y) ? (x) : (y))

namespace Mdl_InOut 
{
	char b[1 << 22], *s = b, *t = b;

	//#define getc() (s == t && (t = (s = b) + fread(b, 1, 1 << 22, stdin), s == t) ? 0 : *s ++)
	#define getc getchar

	inline int Mdl() 
	{
		register int aa = 0, bb = 0; register char ch;
		for (ch = getc(); (ch < '0' || ch > '9') && ch != '-'; ch = getc());
		ch == '-' ? bb = 1 : aa = ch - 48;
		for (ch = getc(); ch >= '0' && ch <= '9'; ch = getc()) aa = aa * 10 + ch - 48;
		return bb ? -aa : aa;
	}

	inline int Mdll() 
	{
		register long long aa = 0, bb = 0; register char ch;
		while (ch = getc(), (ch < '0' || ch > '9') && ch != '-');
		ch == '-' ? bb = 1 : aa = ch - 48;
		while (ch = getc(), ch >= '0' && ch <= '9') aa = aa * 10 + ch - 48;
		return bb ? -aa : aa;
	}

	inline double Mdld() 
	{
		register double aa; register int bb, cc; register  char ch;
		while (ch = getc(), (ch < '0' || ch > '9') && ch != '-');
		ch == '-' ? (bb = 1, aa = 0) : (bb = 0, aa = ch - 48);
		while (ch = getc(), ch >= '0' && ch <= '9') aa = aa * 10 + ch - 48;
		if (ch == '.')
		{
			cc = 1;
			while (ch = getc(), ch >= '0' && ch <= '9') aa += (cc *= 0.1) * (ch - 48);
		}
		return bb ? -aa : aa;
	}

	char Buf[1 << 22], *O = Buf, Stk[150];
	
	inline void Mdo(register int x, register char ch) 
	{
		register int Ts = 0;
		if (!x) *O++ = '0';
		else
		{
			(x < 0) ? x = -x , *O++ = '-' : 1;
			for ( ; x; ) Stk[++ Ts] = x % 10, x /= 10;
			for ( ; Ts; ) *O++ = '0' + Stk[Ts --];
		}
		*O++ = ch;
	}
	
	inline void Mdlo(register long long x, register char ch) 
	{
		register int Ts = 0;
		
		if (!x) *O++ = '0';
		else
		{
			(x < 0) ? x = -x, *O++ = '-' : 1;
			for ( ; x; ) Stk[++ Ts] = x % 10, x /= 10;
			for ( ; Ts; ) *O++ = '0' + Stk[Ts --];
		}
		*O++ = ch;
	}


	inline void Mdlout() 
	{
		fwrite(Buf, 1, O - Buf, stdout),
		O = Buf;
	}
}


using namespace Mdl_InOut;

int W[501], D[1001], Vis[1001];

int main()
{
	register int N = Mdl(), M = Mdl(), Ans = 0;
	for (register int i = 1; i <= N; ++ i)
	{
		W[i] = Mdl();
	}
	for (register int i = 1; i <= M; ++ i)
	{
		D[i] = Mdl();
	}
	for (register int i = 2; i <= M; ++ i)
	{
		for (register int j = 1; j <= M; ++ j) Vis[j] = 0;
		for (register int j = i - 1; j; -- j)
		{
			if (D[i] == D[j]) break ;
			if (!Vis[D[j]])
			{
				Vis[D[j]] = 1, Ans += W[D[j]];
			}
		}
	}
	Mdo(Ans, '\n');
	Mdlout();
	return 0;
}
