\expandafter\ifx\csname classoptions\endcsname\relax
  \def\classoptions{}
\fi
\documentclass[10pt,fykos,\classoptions]{fksempty}

\geometry{ignoreheadfoot,
  a4paper,
  margin=0.7cm,
  headsep=0.2cm}

\usepackage{fkslegacyloader}

\problemsdir{./problems}

% this class doesn't support those, but we use same common
\newcommand{\leftheader}[1]{\relax}
\newcommand{\rightheader}[1]{\relax}
\input{common.tex}

\newcommand\problemtaskbox{%
\noindent\begin{minipage}{\textwidth}
 \problemtask\par
 \vspace{0.5\baselineskip}
 \noindent\makebox[\linewidth]{\rule{\paperwidth}{0.5pt}} 
\end{minipage}\par
\vspace{0.5\baselineskip}
}

% here should be correct number of problems
\begin{document}
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
 \problemtaskbox
\end{document}
