from collections import defaultdict, deque


N, Q = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
idx = defaultdict(list)
for i, a in enumerate(A):
    idx[a].append(i)

INF = 1 << 60
dp = [INF] * N
dp[0] = 0
for b in B:
    que = deque()
    for i in range(N):
        if dp[i] < INF:
            que.append(i)
    l, r = 0, N - 1
    ndp = [INF] * N
    for i in range(N):
        if que and que[0] <= i:
            l = que.popleft()
            if que:
                r = que[0]
            else:
                r = N - 1
        if A[i] == b:
            ndp[i] = min(dp[l] + (i - l), dp[r] + (r - i))
        else:
            ndp[i] = INF
    dp = ndp[:]
print(min(dp))