import java.util.*;
import java.lang.*;
import java.io.*;

public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		//your code 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 b=sc.nextInt();
                int low=0;
                int sum=0;
                for(int i=0;i<n;i++){
                        if(arr[i]>low){
                                low=arr[i];
                        }
                        sum+=arr[i];
                }
                if(b==n){
                        System.out.print(low);
                        return;
                }
                int high=sum;
                int res=0;
                while(low<=high){
                        int mid=low+(high-low)/2;
                        if(isPossible(arr,n,b,mid)==true){
                                res=mid;
                                high=mid-1;
                        }
                        else{
                                low=mid+1;
                        }
                }
                System.out.print(res);
	}
        public static boolean  isPossible(int arr[] , int n, int b, int mid){
                int day=1;
                int sum=0;
                for(int i=0;i<n;i++){
                        sum+=arr[i];
                        if(sum>mid){
                                day++;
                                sum=arr[i];
                        }
                }
                return day<=b;
        }
}