#include<fstream>
#include<deque>
using namespace std;
#define inf 1<<30
deque<int> v;
int main ()
{
	long long minim=1<<30,i,n,k,el,cost=0;
	ifstream fin("deque.in");
	fin>>n>>k;
	for(i=1;i<=n;i++)
	{
		fin>>el;
		if(i>k)
		{
			deque<int>::iterator it;
			minim=inf;
			for(it=v.begin();it!=v.end();it++)
				if(minim>*it) minim=*it;
			cost+=minim;
			v.pop_front();
			v.push_back(el);
		}
		else
		{
			v.push_back(el);
			if(minim>el) minim=el;
		}
	}
	deque<int>::iterator it;
	minim=inf;
	for(it=v.begin();it!=v.end();it++)
		if(minim>*it) minim=*it;
		cost+=minim;
	ofstream fout("deque.out");
	fout<<cost;
	fout.close();
	return 0;
}