Csdrhrt

I want to use documentclass[12pt,a4paper]{article} in the place of documentclass[12pt,reqno]{amsart}. However I want to add the following in the bottom of the first page

This is my codes

documentclass[12pt,a4paper]{report}



 usepackage{geometry}

 geometry{left=3cm,right=2cm,top=2.5cm,bottom=2cm}

 usepackage{setspace}

 onehalfspacing



begin{document}



footnte{2010 Mathematics Subject Classification. Primary ..; Secondary ...}

end{document}

Without using a package:

documentclass[12pt,a4paper]{report}



 usepackage{geometry}

 geometry{left=3cm,right=2cm,top=2.5cm,bottom=2cm}

 usepackage{setspace}

 onehalfspacing



% -------------

makeatletter

defkeywords{xdef@thefnmark{}@footnotetext}

makeatother



begin{document}

    Hello world.%

    keywords{2010 emph{Mathematics Subject Classification.} Primary ..; Secondary dots}%

    keywords{emph{Key words and phrases.} Positive Operator dots}%

    footnote{Normal footnote}

    Some text here.

end{document}

With the titlefoot package:

documentclass[12pt,a4paper]{report}



 usepackage{geometry}

 geometry{left=3cm,right=2cm,top=2.5cm,bottom=2cm}

 usepackage{setspace}

 onehalfspacing



 usepackage{titlefoot}



begin{document}



unmarkedfntext{2010 Mathematics Subject Classification. Primary ..; Secondary ...newlinehspace*{2em}Keywords:}

end{document}