using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {   

        var collection = new object[] { 5, "4545",  'd', 54.5 , 576 };

        var result = collection

     .Where(item => new[] { typeof(string), typeof(int) }.Contains(item.GetType()));

        Console.WriteLine(string.Join("\n", result));

    }

}