#include <bits/stdc++.h>
#define int long long
using namespace std;

ifstream fin("deque.in");
ofstream fout("deque.out");

int n, k;
deque<int> dq;
set<int> minime;

signed main()
{
    fin >> n >> k;
    int sum = 0;
    for(int i = 1; i <= n; i++)
    {
        int x;
        fin >> x;
        dq.push_back(x);
        if(dq.size() <= k)
        {
            minime.insert(x);
        }
        else{
            sum += *minime.begin();
            minime.erase(dq.front());
            minime.insert(x);
            dq.pop_front();
        }
    }
    sum += *minime.begin();
    fout << sum;
    return 0;
}