\let\fin=\end
\def\end{}
\input prob1.tex
\bigskip
\input prob2.tex
\bigskip
\input prob3.tex
\bigskip
\input prob4.tex
\bigskip
\input prob4a.tex
\bigskip
\input prob4b.tex
\bigskip
\input prob5.tex
\bigskip
\input prob6.tex
\bigskip
\input prob7.tex
\bigskip
\input prob8.tex
\fin
