using System;

using System.Collections;

public class Program

{

    public static void Main()

    {

        //Console.WriteLine("Hello World");

        int[] arr = {1,2,4,4};

        int result = getMinimumUniqueSum(arr);

        Console.WriteLine(result);

    }

    public static int getMinimumUniqueSum(int[] arr){

    int sum = 0, val = 0;

    ArrayList arrayList = new ArrayList();

    arrayList.Add(arr[0]);

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

        val = arr[i];

        while (arrayList.Contains(val)) {

            val++;

        }

        arrayList.Add(val);    

    }

    foreach (var item in arrayList) {

        //Console.WriteLine(item);

        sum += Convert.ToInt32(item);

    }

    return sum;

}

}