// There are N oil derricks in the area. The main oil pipeline will go through the area

// strictly from east to west, but its northern coordinate is negotiable. Each derrick must be

// connected directly to the main pipeline with its own pipe. Find the y-position of the

// main pipeline that will lead to minimal total length of all pipes coming from the derricks

// to this main pipeline.

​

using System;

public class Program

{

    public static void Main(string[] args)

    {

        int[] x = {1, 2, 3, 4, 5, 8, 13};

        int[] y = {1, 3, 4, 5, 6, 7, 11};

        Console.WriteLine(bestY(x, y));

    }

    public static int bestY(int[] x,int[] y)

    {

        Array.Sort(y);

        return y[y.Length/2];

        // Time complexity: O(n log n)

    }

}