import java.util.*;
import java.io.*;
 
public class Main
{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int[]nums =new int[n];
		for(int i=0;i<n;i++){
		    nums[i]=sc.nextInt();
		}
 
		int y=sc.nextInt();
		int x=sc.nextInt();
 
		int res= Integer.MAX_VALUE;
		int sum=0;
		int count=0; //for selecting only x elements
		for(int j=0;j<n;j++){
		   sum=nums[j];
		   count++;
 
		   int z=j-y;
		   while(z >=0 && count-x <0){
		      sum+=nums[z];
		      z=z-y;
		      count++;
		   } 
		   if(count == x ){
		       res= Math.min(res,sum);
		   }
		   count=0;
		   sum=0;
		}
		System.out.print(res);
	}
}

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