import java.util.*;

public class Main {
    static int cnt=0,n,m,w[],temp[];
    public static void main(String[] args){
     Scanner scan = new Scanner(System.in);
     n = scan.nextInt();
     m= scan.nextInt();
     w=new int[n];
     for(int i=0;i<n;i++){
         w[i]=scan.nextInt();
       }
     temp=Arrays.copyOfRange(w,0,m);
     if(n==m){
     System.out.println(Arrays.stream(w).max().getAsInt());
        }else{

            for(int i=m;i<n;i++){
                int min=Arrays.stream(temp).min().getAsInt();
         for(int j=0;j<temp.length;j++){
                    temp[j]-=min;
                    if(temp[j]==0){
                        temp[j]=w[i];
                    }
                }

                cnt+=min;

            }
 cnt+=Arrays.stream(temp).max().getAsInt();
        }

        System.out.println(cnt);
        scan.close();
    }

}