public static void main(String[] args) {
      String sCurrentLine;
      int i=1;
        BufferedReader br = null;
       Writer writer = null;
        try {

                        String myDocumentPath = System.getProperty("user.home") + "\\Documents"+ "\\iMacros" + "\\Macros";
                        String code="";
          writer = new BufferedWriter(new OutputStreamWriter(
          new FileOutputStream(myDocumentPath+File.separator+"usernames1.txt"), "utf-8"));
            br = new BufferedReader(new FileReader(myDocumentPath+"\\list.txt"));

            while ((sCurrentLine = br.readLine()) != null) {
                            if(i<4)
                            {

                                code="@"+sCurrentLine+" ";
                                i++;
                                System.out.print(code);


                            }
                            else
                            {
                             code=code+"\n";
                            writer.write(code);
                            code="";
                            i=0;
                            }
            }

        } catch (IOException e) {
            e.printStackTrace();
        }

}