#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
//1-indexed
#include<vector>
template<typename T>
struct BIT{
	int n;
	vector<T>bit;
	BIT(int n_=0):n(n_),bit(n_+1){}
	T sum(int i)
	{
		T ans=0;
		for(;i>0;i-=i&-i)ans+=bit[i];
		return ans;
	}
	void add(int i,T a)
	{
		if(i==0)return;
		for(;i<=n;i+=i&-i)bit[i]+=a;
	}
	int lower_bound(T k)//k<=sum(ret)
	{
		if(k<=0)return 0;
		int ret=0,i=1;
		while((i<<1)<=n)i<<=1;
		for(;i;i>>=1)
			if(ret+i<=n&&bit[ret+i]<k)k-=bit[ret+=i];
		return ret+1;
	}
};
int N,K;
int A[1<<17];
main()
{
	cin>>N>>K;
	vector<long>val(N);
	for(int i=0;i<N;i++)
	{
		cin>>A[i];
		val[i]=A[i];
	}
	sort(val.begin(),val.end());
	val.erase(unique(val.begin(),val.end()),val.end());
	for(int i=0;i<N;i++)
	{
		A[i]=lower_bound(val.begin(),val.end(),A[i])-val.begin()+1;
	}
	BIT<int>Pc(val.size());
	BIT<long>Ps(val.size());
	for(int i=0;i<K-1;i++)
	{
		Pc.add(A[i],1);
		Ps.add(A[i],val[A[i]-1]);
	}
	long ans=9e18;
	for(int i=K-1;i<N;i++)
	{
		Pc.add(A[i],1);
		Ps.add(A[i],val[A[i]-1]);
		int mid=Pc.lower_bound((K+1)/2);
		ans=min(ans,Ps.sum(val.size())-Ps.sum(mid)-val[mid-1]*(Pc.sum(val.size())-Pc.sum(mid))
			+val[mid-1]*Pc.sum(mid)-Ps.sum(mid));
		Pc.add(A[i-(K-1)],-1);
		Ps.add(A[i-(K-1)],-val[A[i-(K-1)]-1]);
	}
	cout<<ans<<endl;
}