using System;

public class Program

{

    public static void Main()

    {

        int[] arr = {2,3,10,6,4,8,1};

        StockBuyNSell s = new StockBuyNSell();

        Console.WriteLine(s.FindMaxDifference(arr));

    }

}

​

public class StockBuyNSell {

    public int FindMaxDifference(int[] arr) {

        int max_diff = arr[1] - arr[0];

        int min_element = arr[0];

        for(int i=1; i<arr.Length; i++) {

            if(arr[i] - min_element > max_diff) {

                max_diff = arr[i] - min_element;

            }

            if(arr[i] <min_element){

                min_element = arr[i];

            }

        }

        return max_diff;

    }

}

​