using System;

using System.Linq;

using System.Collections;

public class Program

{

    public static void Main()

    {

​

    System.Collections.Generic.IEnumerable<Person> personList = new Person[] 

    { 

         new Person { Name = "Mahsa", Id = 125 }, 

         new Person { Name = "Kashi", Id = 234 }, 

         new Person { Name = "Hassankashi", Id = 750 },

         new Person { Name = "Sara", Id = 723 },

         new Person { Name = "Mana", Id = 125 },

         new Person { Name = "Rana", Id = 325 },

    };

        System.Collections.Generic.IEnumerable<Person> personList2 = new Person[] 

    { 

         new Person { Name = "Mahsa", Id = 125 }, 

         new Person { Name = "Kashi", Id = 234 }, 

         new Person { Name = "Sara", Id = 750 },

         new Person { Name = "Hassankashi", Id = 723 },

         new Person { Name = "Mana", Id = 125 },

         new Person { Name = "Rana", Id = 325 },

    };

int currentIndex = 2;

Person c = personList.ElementAt(currentIndex); //3th -> Name = "Hassankashi", Id = 750

​

Person c2 = personList2.ElementAt(currentIndex); //3th -> Name = "Hassankashi", Id = 750

​

​

//Person c = personList.ElementAtOrDefault(currentIndex); 

        Console.WriteLine(personList.Except(personList2));

    }

    public class Person

    {

        public string Name {get; set;}

        public int Id {get; set;}

    }

}