using System;

public class Program

{

    public const int MaxLen = 10001;

    public static int GetMaxPoints(int[] nums) 

    {

        var count = new int[MaxLen];

        foreach(var num in nums)

            count[num] += num;

​

        int next = 0, previous = 0, current = 0;        

​

        for(int i = 0; i < MaxLen; i++)

        {

            next = Math.Max(previous + count[i], current);

            previous = current;

            current = next;

        }

​

        return next;

    }

    public static void Main()

    {

        Console.WriteLine("UniLecs");

        // tests

        Console.WriteLine(GetMaxPoints(new int[] { 3, 4, 2 }).ToString()); // 6

        Console.WriteLine(GetMaxPoints(new int[] { 2, 2, 3, 3, 3, 4 }).ToString()); // 9

    }

}