\documentclass{article}

\usepackage[T2A]{fontenc}
\usepackage[russian,english]{babel}
\usepackage[utf8]{inputenc}
\usepackage{amsmath,amssymb}
\usepackage{tikz}

\begin{document}

\pagestyle{empty}

\vspace*{-4em}
\begin{tikzpicture}
	\draw[help lines] (0,0) grid (5,5);
	\draw [<->,thick] (0,5.5) node [above] {$y$} |- (5.5,0) node [right] {$x$};
	\foreach \x in {1, ..., 5} \node[below] at (\x,0) {$\x$};
	\foreach \y in {1, ..., 5} \node[left] at (0,\y) {$\y$};

	\draw [<->,thick] (0.5,1) node {} |- (1,0.5) node {};
	\fill (0.5,0.5) circle (0.1);
	\node[circle, draw]  at (4.5,4.5) {\bf x};
	\foreach \x/\y in {1/1, 1/3}
		\fill (\x,\y) rectangle (\x+1,\y+1);
	\foreach \x/\y/\n in {2/3/7, 0/3/8, 2/1/2}
		\node[circle,draw] at (\x+0.5,\y+0.5) {$\n$};
\end{tikzpicture}

\end{document}