\documentclass{../Lecture}

\usepackage{../preamble}
% \newtheorem{theorem}{Теорема}

\title{Криптографические методы защиты информации}
\author{Андрей Гущин}
\date{\today}

\begin{document}

\maketitle
\tableofcontents
\thispagestyle{empty}
\newpage

\input{lectures/lecture1.tex}
\input{lectures/lecture2.tex}
\input{lectures/lecture3.tex}
\input{lectures/lecture4.tex}
\input{lectures/lecture5.tex}
\input{lectures/lecture6.tex}
\input{lectures/lecture7.tex}
\input{lectures/lecture8.tex}
\input{lectures/lecture9.tex}
\input{lectures/lecture10.tex}
\input{lectures/lecture11.tex}
\input{lectures/lecture12.tex}
\input{lectures/lecture13.tex}
\input{lectures/lecture14.tex}
\input{lectures/lecture15.tex}

\end{document}