using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        int[] numbers = {1,5,2,9,7,3,6};

        int n = 3;

        int nthHighest = FindNthHighest(numbers, n);

        Console.WriteLine(n);

    }

​

    static int FindNthHighest(int[] array, int n)

    {

        SortedSet<int> sort = new SortedSet<int>();

        foreach (int i in array)

        {

            sort.Add(i);

            if (sort.Count > n)

            {

                sort.Remove(sort.Min);

            }

        }

​

        return sort.Min;

    }

}