import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        long total = 0;
        int[] values = new int[n + 2];
        for (int i = 1; i <= n; i++) {
            values[i] = sc.nextInt();
            total += values[i];
        }
        Sushi[] sushies = new Sushi[n + 2];
        sushies[0] = new Sushi(0, 0);
        TreeSet<Sushi> mins = new TreeSet<>();
        mins.add(sushies[0]);
        for (int i = 1; i <= n + 1; i++) {
            sushies[i] = new Sushi(i, mins.first().value + values[i]);
            mins.add(sushies[i]);
            if (i - k >= 0) {
                mins.remove(sushies[i - k]);
            }
        }
        System.out.println(total - sushies[n + 1].value);
    }
    
    static class Sushi implements Comparable<Sushi> {
        int idx;
        long value;
        
        public Sushi(int idx, long value) {
            this.idx = idx;
            this.value = value;
        }
        
        public int hashCode() {
            return idx;
        }
        
        public int compareTo(Sushi another) {
            if (value == another.value) {
                return idx - another.idx;
            } else if (value < another.value) {
                return -1;
            } else {
                return 1;
            }
        }
        
        public boolean equals(Object o) {
            return hashCode() == o.hashCode();
        }
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}