N,K = map(int,input().split())
A = sorted(list(map(int,input().split())))
ans = sum(A)
if K==1:
    ans = A[N-1]-A[0]
elif K==2:
    for i in range(1,N):
        cnt = A[i-1]-A[0]+A[N-1]-A[i]
        ans = min(ans,cnt)
else:
    for i in range(1,N-K+2):
        cnt = A[i-1]-A[0]+A[N-1]-A[i+K-2]
        ans = min(ans,cnt)
print(ans)