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 sys
t,n = [int(x) for x in sys.stdin.readline().split()]
w = [int(x) for x in sys.stdin.readline().split()]
books = [int(x)-1 for x in sys.stdin.readline().split()]

len_book = len(w)
weights = 0

# for i in range(1,len(books)):
# 	startind = max(0,i-len_books+1)
# 	bookarr = list(books[startind+1:i+1])
# 	bookarr.remove(books[i])
# 	print bookarr,books[i]
# 	weights += sum(w[i] for i in bookarr)

arlist = []
booklist = []
for i in books:
	if i not in booklist:
		arlist.append(w[i])
		booklist.append(i)
weights = 0

for i in books:
	for j in range(len(booklist)):
		if booklist[j]==i:
			art = arlist[j]
			del arlist[j]
			del booklist[j]
			arlist.insert(0,art)
			booklist.insert(0,i)
			break
		else:
			weights += arlist[j]

print weights