using System;

public class Largest

{

​

    public static int ThirdLargest(int[] input)

    {

        int firstLargest = 0;   

        int secondLargest = 0;

        int thirdLargest = 0;

​

        for(int i=0; i<input.Length; i++)

        {

           if(input[i] > firstLargest)

           {

                thirdLargest = secondLargest;

                secondLargest = firstLargest;  

                firstLargest = input[i];

           }

            else if(input[i] > secondLargest)

            {

                thirdLargest = secondLargest;

                secondLargest = input[i];  

            }

            else if(input[i] > thirdLargest)

            {

                thirdLargest = input[i];  

            }

        }

        return thirdLargest;

    }

}

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine(Largest.ThirdLargest(new int[]{12,5,24,537,53}));

    }

}