Ussing files StreamWriter and StreamReader

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication3
{
    class Program
    {
        
static void Main(string[] args)
        {
            double pi = Math.PI;
            FileStream f = new FileStream("file.txt",FileMode.OpenOrCreate,FileAccess.ReadWrite,FileShare.ReadWrite);
            try
            {
                using(StreamWriter sw = new StreamWriter(f))
                {
                    String userinput = Console.ReadLine();
                    if (f.Length > 1)
                    {
                        sw.Write(userinput);
                        sw.Write("\r\n");
                    }
                    else
                    {
                        sw.WriteLine(userinput);
                        sw.Write("\r\n");
                    }
                }
                
            }
            catch(IOException ioe)
            {
                Console.WriteLine(ioe);
            }
            catch(Exception e)
            {
                Console.WriteLine(e);
            }
            int line;
            using (StreamReader sr = new StreamReader("file.txt"))
            {
                try
                {
                    Console.WriteLine(sr.ReadToEnd());
                    Console.ReadKey();
                }
                catch(Exception e)
                {
                    Console.WriteLine(e);
                }
                
            }
        }
    }
}