N,Q = map(int,input().split())
A = [0]+list(map(int,input().split()))
B = [0]+list(map(int,input().split()))
C = {}
for i in range(1,N+1):
    a = A[i]
    if a not in C:
        C[a] = []
    C[a].append(i)
INFTY = 10**10
dp = [[INFTY for _ in range(N+1)] for _ in range(Q+1)]
for j in C[B[Q]]:
    dp[Q][j] = 0
for i in range(Q-1,0,-1):
    for j in C[B[i]]:
        for k in C[B[i+1]]:
            dp[i][j] = min(dp[i][j],abs(j-k)+dp[i+1][k])
ans = INFTY
for j in C[B[1]]:
    ans = min(ans,dp[1][j]+j-1)
print(ans)