from bisect import bisect_left

N, Q = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

IDX = dict()
for i in range(N):
    if A[i] not in IDX:
        IDX[A[i]] = [i]
    else:
        IDX[A[i]].append(i)

INF = 10**18
dp = [[INF]*N for _ in range(Q+1)]
dp[0][0] = 0
for i in range(Q):
    for j in range(N):
        if dp[i][j] != INF:
            if A[j] == B[i]:
                dp[i+1][j] = min(dp[i+1][j], dp[i][j])
            else:
                b = bisect_left(IDX[B[i]], j)
                if b >= 1:
                    dp[i+1][IDX[B[i]][b-1]] = min(dp[i+1][IDX[B[i]][b-1]], dp[i][j]+abs(IDX[B[i]][b-1]-j))
                if b < len(IDX[B[i]]):
                    dp[i+1][IDX[B[i]][b]] = min(dp[i+1][IDX[B[i]][b]], dp[i][j]+abs(IDX[B[i]][b]-j))

print(min(dp[-1]))