How can I remove the up arrowheads at the right side and why they are appear? thanks a lot !
\documentclass[a4paper,twoside,10pt]{memoir}
\usepackage{alphabeta}
\def\eng#1{\textlatin{#1}}
\usepackage{textcase}
\usepackage{silence}
\usepackage{kerkis}
\usepackage{color}
\usepackage[svgnames,x11names,named]{xcolor}
\WarningFilter*{mdframed}{You got a bad break}
\WarningFilter{latex}{Text page}
\usepackage[usetwoside]{mdframed}
\usepackage[LGR,T1]{fontenc}
\usepackage{anyfontsize}
\usepackage{lipsum}
\usepackage {tikz}
\usetikzlibrary {positioning,graphs,calc,decorations.pathmorphing,shapes,arrows.meta,arrows,bending,decorations.markings}
\usepackage{graphicx}
\usepackage{stix}
\usepackage{amsmath}
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\usepackage{amsfonts}
\usepackage{amsthm}
\usepackage{mathtools}
\usepackage{systeme}
\usepackage{wrapfig}
\usepackage{afterpage}
\usepackage{tocloft}
\usepackage[figuresright]{rotating}
\usepackage{parskip}
\usepackage{caption}
\usepackage{enumitem}
\usepackage{titletoc}
\usepackage{calc}
\usepackage{pstricks}
\usepackage{bbm}
\usepackage{textcomp}
\usepackage{upgreek}
\usepackage{ifthen}
\usepackage{extramarks}
\usepackage{bm}
\usepackage{multirow}
\usepackage{multicol}
\usepackage{colortbl}
\begin{document}
\begin{center}
\tikzset{every loop/.style={min distance=15mm,looseness=10}}
\begin{tikzpicture}[-latex ,auto ,node distance =1cm and 1cm, on grid,semithick ,
state/.style ={circle, draw, color=black , fill=cyan!20, text=black , minimum width =0.2 cm}]
\draw (1,4) node [state][rectangle] (a1) {$\bm{w}$};
\draw (3,6) node [state][rectangle] (b2) {$\bm{wx}$};
\draw (3,1) node [state][rectangle] (a2) {$\bm{wv}$};
\draw (6,8) node [state][rectangle] (c3) {$\bm{wxx}$};
\draw (6,5) node [state][rectangle] (b3) {$\bm{wxv}$};
\draw (6,1) node [state][rectangle] (a3) {$\bm{wvx}$};
\draw (8,9) node [state][rectangle] (e4) {$\bm{wxxx}$};
\draw (8,7) node [state][rectangle] (d4) {$\bm{wxxv}$};
\draw (8,5) node [state][rectangle] (c4) {$\bm{wxvx}$};
\draw (8,2) node [state][rectangle] (b4) {$\bm{wvxx}$};
\draw (8,0) node [state][rectangle] (a4) {$\bm{wvxv}$};
\draw (10,0) node [state][rectangle] (a5) {$\bm{wvxvv}$};
\draw (10,1) node [state][rectangle] (b5) {$\bm{wvxxv}$};
\draw (10,3) node [state][rectangle] (c5) {$\bm{wvxxx}$};
\draw (10,4) node [state][rectangle] (d5) {$\bm{wxvxv}$};
\draw (10,6) node [state][rectangle] (e5) {$\bm{wxvxx}$};
\draw (10,7) node [state][rectangle] (f5) {$\bm{wxxvx}$};
\draw (10,8) node [state][rectangle] (g5) {$\bm{wxxxv}$};
\draw (10,10) node [state][rectangle] (h5) {$\bm{wxxxx}$};
\draw (12,10.2) node [draw=none,fill=none] (p1) {};
\draw (12,9.8) node [draw=none,fill=none] (p2) {};
\draw (12,8) node [draw=none,fill=none] (p3) {};
\draw (12,7.2) node [draw=none,fill=none] (p4) {};
\draw (12,6.8) node [draw=none,fill=none] (p5) {};
\draw (12,5.8) node [draw=none,fill=none] (p6) {};
\draw (12,6.2) node [draw=none,fill=none] (p7) {};
\draw (12,4) node [draw=none,fill=none] (p8) {};
\draw (12,3.2) node [draw=none,fill=none] (p9) {};
\draw (12,2.8) node [draw=none,fill=none] (p10) {};
\draw (12,1) node [draw=none,fill=none] (p11) {};
\draw (12,0.2) node [draw=none,fill=none] (p12) {};
\draw (12,-0.2) node [draw=none,fill=none] (p13) {};
\path (a1) edge (a2);
\path (a1) edge (b2);
\path (a2) edge (a3);
\path (b2) edge (c3);
\path (b2) edge (b3);
\path (a3) edge (a4);
\path (a3) edge (b4);
\path (b3) edge (c4);
\path (c3) edge (d4);
\path (c3) edge (e4);
\path (a4) edge (a5);
\path (b4) edge (b5);
\path (b4) edge (c5);
\path (c4) edge (d5);
\path (c4) edge (e5);
\path (d4) edge (f5);
\path (e4) edge (g5);
\path (e4) edge (h5);
\path (h5) edge [dashed] (p1);
\path (h5) edge [dashed] (p2);
\path (g5) edge [dashed] (p3);
\path (f5) edge [dashed] (p4);
\path (f5) edge [dashed] (p5);
\path (e5) edge [dashed] (p6);
\path (e5) edge [dashed] (p7);
\path (d5) edge [dashed] (p8);
\path (c5) edge [dashed] (p9);
\path (c5) edge [dashed] (p10);
\path (b5) edge [dashed] (p11);
\path (a5) edge [dashed] (p12);
\path (a5) edge [dashed] (p13);
\end{tikzpicture}
\end{center}
\end{document}