import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] reels = new int[n];
        for (int i = 0; i < n; i++) {
            reels[i] = input.nextInt();
        }
        int editors_count = input.nextInt();

        int low = max(reels);
        int high = sum(reels);
        while (low < high) {
            int mid = (low + high) / 2;
            int editors_needed = 1;
            int current_time = 0;
            for (int reel : reels) {
                if (current_time + reel <= mid) {
                    current_time += reel;
                } else {
                    editors_needed++;
                    current_time = reel;
                }
            }
            if (editors_needed <= editors_count) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        System.out.println(low);
    }

    private static int max(int[] arr) {
        int max = Integer.MIN_VALUE;
        for (int num : arr) {
            max = Math.max(max, num);
        }
        return max;
    }

    private static int sum(int[] arr) {
        int sum = 0;
        for (int num : arr) {
            sum += num;
        }
        return sum;
    }
}