Starting page number getting in .aux file

How to get starting pagenumber getting in .aux file?
we have option to get lastpage number using "lastpage.sty" to print in .log file,
we need same way to get first page number via .aux file?

Please find MWE file is as follows:

documentclass{book}
usepackage{lastpage}

begin{document}
sample
clearpage
sample
clearpage
sample 
end{document}

Aux file output:

relax
newlabel{LastPage}{{}{3}}
xdeflastpage@lastpage{3}
gdeflastpage@lastpageHy{}