/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	private static int solve(int n, int[]arr, int k){
		int[] dp = new int[n+1];
		dp[0] = 0;
		SortedSet<Integer> set = new TreeSet<>();
		set.add(0);
 
		for(int i = 1; i<n+1; i++){
			dp[i] = set.first() + arr[i-1];
			set.add(dp[i]);
			if(i>k-1) set.remove(dp[i-k]);
		}
		return dp[n];
	}
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for(int i = 0; i<n; i++)arr[i] = sc.nextInt();
		int k = sc.nextInt();
 
		System.out.println(solve(n,arr,k));
	}
}

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