\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\title{Derevyannykh.2.7}
\author{devmishok }
\date{July 2018}

\begin{document}

\maketitle

\section{Task7}

\begin{tikzpicture}[
squarenode/.style={rectangle, draw=black!60, fill=green!5, thick, minimum size=5mm},
roundnode/.style={circle, draw=black!60, fill=white!5, thick, minimum size=3mm}
]
\node[squarenode] (T1) {$T1$}
\node[roundnode] (P1) [right of=T1] {$p1$}
\node[squarenode] (T2) [right of=P1] {$T2$}
\node[roundnode] (P2) [right of=T2] {$p2$}
\node[squarenode] (T3) [right of=P2] {$T3$}
\node[roundnode] (CP2) [below left of=T3] {$cp2$}
\node[roundnode] (CP1) [below left of=T2] {$cp1$}

\draw[->] (T1.east) -- (P1.west);
\draw[->] (P1.east) -- (T2.west);
\draw[->] (T2.east) -- (P2.west);
\draw[->] (P2.east) -- (T3.west);
\draw[->] (T3.south) -- (CP2.east);
\draw[->] (CP.west) -- (T2.south);
\draw[->] (T2.south) -- (CP1.east);
\draw[->] (CP1.west) -- (T1.south);

\end{tikzpicture}




\end{document}