\documentclass[a4paper,12pt,fleqn]{article} %extreport
\usepackage[top=3cm,bottom=1cm,left=2cm,right=2cm]{geometry}
\usepackage{fancyhdr,color,xcolor,dsfont}
\usepackage{listings,ulem,booktabs,graphics,lastpage}
\usepackage{bm,amsmath,amssymb,amsthm,latexsym}
\usepackage{graphicx,fouriernc,hyperref} %fouriernc
\pagestyle{fancy}
\fancyhf{}
\lhead{Macro theory IV:HW1}
\chead{}
\rhead{ d96627003 Chang,JunXiang \quad \thepage/\pageref{LastPage} }
%\usepackage{pifont} fouriernc mathpazo concmath(it can’t use pdf) mathptmx
\def\be{\begin{enumerate}} % Begin Enumerate
\def\ee{\end{enumerate}} % End Enumerate
\def\en{\item} % ENtry (item)
\def\bi{\begin{itemize}} % Begin Itemize
\def\ei{\end{itemize}} % End Itemize
\def\[#1\]{\begin{align*}#1\end{align*}}
\DeclareSymbolFont{letters}{OML}{ccm}{m}{it}
\DeclareMathAlphabet{\mathcal}{OMS}{cmsy}{m}{n}
\renewcommand{\labelitemi}{$\blacktriangleright$}
\newcommand{\nf}{\textrm}
\newcommand{\dsp}{\displaystyle}
\newcommand{\intff}{\int^{\infty}_{0}}
\newcommand{\ert}{e^{-R(t)}}
\newcommand{\ev}{\mathcal{V}}
\newcommand{\dpa}{\partial}
\newcommand{\lw}{\leftarrow}
\newcommand{\llw}{\Leftarrow}
\newcommand{\rw}{\rightarrow}
\newcommand{\rrw}{\Rightarrow}
\newcommand{\ham}{\mathcal{H}}
\newcommand{\lam}{\pounds}
\newcommand{\grl}{\lambda}
\newcommand{\gra}{\alpha}
\newcommand{\grb}{\beta}
\newcommand{\grd}{\delta}
\newcommand{\grt}{\theta}
\newcommand{\limu}{\lim_{t\rw \infty}}
\newcommand{\cov}{\mathsf{Cov}}
\newcommand{\ex}{\mathds{E}}
\newcommand{\bx}{\pmb{X}}
\newcommand{\bgrb}{\pmb{\beta}}
\newcommand{\bgrt}{\pmb{\theta}}
\newcommand{\bA}{\pmb{A}}
\newcommand{\bu}{\pmb{u}}
\newcommand{\bve}{\pmb{\varepsilon}}
\newcommand{\lp}{\mathds{L}}
\newcommand{\I}{\nf{I}}
\newcommand{\iid}{\stackrel{\mathrm{iid}}{\sim}}
\linespread{1.3}
\pagecolor{white}
\color{black}
%=========================here start=======================%
\begin{document}