begin{filecontents}{File1.tex}
currfilename
begin{itemize}
item first
end{itemize}
end{filecontents}

begin{filecontents}{File2.tex}
currfilename
begin{itemize}
item first
item second
end{itemize}
end{filecontents}

begin{filecontents}{File3.tex}
currfilename
begin{itemize}
item first
item second
item third
end{itemize}
end{filecontents}

begin{filecontents}{File4.tex}
currfilename
begin{itemize}
item first
item second
item third
item fourth
end{itemize}
end{filecontents}


documentclass[10pt]{article}
usepackage{currfile}

begin{document}

input{File1.tex}
input{File2.tex}
input{File3.tex}
input{File4.tex}

end{document}