#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
 
ifstream fin("deque.in");
ofstream fout("deque.out");
 
const int MAX_SIZE = 5000005;
int v[MAX_SIZE], n, k;
int minimums[MAX_SIZE], pos = 0;

int main() {
    fin >> n >> k;
    int cnt = 0;
    for (int i = 1; i <= n; ++i) {
        fin >> v[i];
    }
    int sum = 0;
    for (int i = 1; i <= n + 1; ++i) {
        if (i > k) {
            ++cnt;
            sum += minimums[cnt];
        }
        int j = i;
        while (j > cnt) {
            if (minimums[j] > v[i]) {
                minimums[j] = v[i];
            } else {
                break;
            }
            --j;
        }
        minimums[++pos] = v[i];
    }
    fout << sum;
}