/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package deposit;

/**
 *
 * @author 100622796
 */
import java.util.*;

public class Deposit {

    /**
     * @param args the command line arguments
     */
    int x0, x1, y;
    boolean extracted;

    public Deposit(int x0, int x1, int y) {
        this.x0 = x0;
        this.x1 = x1;
        this.y = y;
    }

    public static boolean isBetween(int startX, int startY, int endX, int endY, Deposit deposit) {
        double slope, b;

        if (startY != endY) {
            slope = (double) (endY - startY) / (double) (endX - startX); // calculate slope of the well
            b = startY - (double) (slope * startX); // calculate intercept
            double depoPoint = (deposit.y - b) / slope;
            depoPoint = Math.round(depoPoint);
            return (depoPoint >= deposit.x0 && depoPoint <= deposit.x1);
        }
        return false;
    }

    public static void drillWell(Deposit[] depoArray) {
        int totalOil = 0;
        ArrayList<Integer> oilList = new ArrayList<Integer>();

        int pointArray[] = new int[depoArray.length * 2];
        for (int i = 0; i < pointArray.length; i = i + 2) {
            pointArray[i] = depoArray[i / 2].x0;
            pointArray[i + 1] = depoArray[i / 2].x1;
        }
        for (int i = 0; i < pointArray.length; i++) {
            totalOil = 0;
            if (i % 2 == 0) {
                for (int j = i + 2; j < pointArray.length; j++) {
                    totalOil = 0;
                    for (int k = 0; k < depoArray.length; k++) {
                        if (isBetween(pointArray[i], depoArray[(i / 2)].y, pointArray[j], depoArray[j / 2].y, depoArray[k]) && !(depoArray[i / 2].y == depoArray[j / 2].y)) {
                            totalOil = totalOil + (depoArray[k].x1 - depoArray[k].x0);
                            oilList.add(totalOil);
                        }
                    }

                }
            } else {
                for (int j = i + 1; j < pointArray.length; j++) {
                    totalOil = 0;
                    for (int k = 0; k < depoArray.length; k++) {
                        if (isBetween(pointArray[i], depoArray[(i / 2)].y, pointArray[j], depoArray[j / 2].y, depoArray[k]) && !(depoArray[i / 2].y == depoArray[j / 2].y)) {
                            totalOil = totalOil + (depoArray[k].x1 - depoArray[k].x0);
                            oilList.add(totalOil);
                        }
                    }
                }
            }
        }
        System.out.println("largest value = " + Collections.max(oilList));
    }

    /*
    public static void sort(Deposit arr[]) {
        int n = arr.length;
        for (int i = 1; i < n; ++i) {
            int key = arr[i].y;
            int j = i - 1;

            /* Move elements of arr[0..i-1], that are
               greater than key, to one position ahead
               of their current position
            while (j >= 0 && arr[j].y > key) {
                arr[j + 1].y = arr[j].y;
                j = j - 1;
            }
            arr[j + 1].y = key;
        }
    } */

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter the number of deposits.");
        int numOfDeposits = input.nextInt();
        Deposit[] deposits = new Deposit[numOfDeposits];
        int start, finish, temp;

        System.out.println("Enter the information of each deposit.");
        for (int i = 0; i < numOfDeposits; i++) {
            start = input.nextInt();
            finish = input.nextInt();
            if (start > finish) {
                temp = start;
                start = finish;
                finish = temp;
            }
            deposits[i] = new Deposit(start, finish, input.nextInt());
        }
        drillWell(deposits);
    }

}