import sys
input = sys.stdin.readline

from collections import defaultdict
from bisect import bisect

N,Q=map(int,input().split())

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

S=sorted(set(sorted(A)))
D={S[i]:i for i in range(len(S))}

for i in range(N):
    A[i]=D[A[i]]

for i in range(Q):
    B[i]=D[B[i]]

D=defaultdict(list)

for i in range(N):
    D[A[i]].append(i)

DP=[1<<60]*N
DP[0]=0

for i in range(Q):
    NDP=[1<<60]*N

    for j in range(N):
        if DP[j]!=1<<60:
            x=bisect(D[B[i]],j)
            #print(x,D[B[i]])

            for y in range(x-2,x+2):
                if 0<=y<len(D[B[i]]):
                    NDP[D[B[i]][y]]=min(NDP[D[B[i]][y]],DP[j]+abs(D[B[i]][y]-j))
    DP=NDP
    
print(min(DP))