\usepackage[T1,T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english,russian]{babel}
\usepackage[labelformat=empty]{caption}
\usepackage{listings}
\usepackage{url}

% narrow margins
% https://en.wikibooks.org/wiki/LaTeX/Page_Layout#Margins
\usepackage[cm]{fullpage}

\usepackage{fontspec}
\setmainfont{FreeSerif}
\setsansfont{FreeSerif}
\setmonofont{FreeMono}

\lstset{
        basicstyle=\footnotesize\ttfamily,
        breaklines=true,
}