missing number between 1 -100 ?

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace naturalNumber

{

   class Program

   {

       static void Main(string[] args)

       {

           int[] arr = new int[5];

           int sum = 0,total,miss;

           total = 5*(5+1)/2;

           Console.WriteLine("Enter the value");

           for (int i = 0; i < 5; i++)

           {

               arr[i] = Int32.Parse(Console.ReadLine()

);

               sum = sum + arr[i];

           }

          miss = total - sum;

           Console.WriteLine("number is " + miss);

       }

   }

}