\( % theorem \newenvironment{pf}{\textbf{Proof.}}{\rule{1ex}{1ex}} \newtheorem{qu}{Question} \newtheorem{thm}{Theorem} \newtheorem{rmk}{Remark} \newtheorem{go}{Goal} \newtheorem{df}{Definition} \newtheorem{prop}{Proposition} \newtheorem{mot}{Motivation} \newtheorem{ex}{Example} \lstnewenvironment{code}{}{} \newcommand{\nc}{\newcommand} %% env \nc{\env}[2]{ \begin{#1} #2 \end{#1} } \nc{\arr}[2]{ \begin{array}{#1} #2 \end{array} } \nc{\arrb}[2]{ \left\{ \begin{array}{#1} #2 \end{array} \right. } \nc{FTC}[3]{ \left[#3\right]^{#2}_{#1} } \nc{\bracs}[1]{ \left[#1\right] } \nc{\brac}[1]{ \left(#1\right) } \nc{\bracp}[1]{ \left\{#1\right\} } \nc{\intd}[4]{\int^{#2}_{#1}\left(#3\right) #4} % shortcut \nc{\Lra}{\Leftrightarrow} \nc{\Ra}{\Rightarrow} \nc{\La}{\Leftarrow} \nc{\C}{\mathbb{C}} \nc{\R}{\mathbb{R}} \nc{\Fc}{\mathcal{C}} \nc{\bds}{\boldsymbol} \nc{\ds}{\displaystyle} % begin end \nc{\bit}{\begin{itemize}} \nc{\eit}{\end{itemize}} \nc{\bcode}{\begin{code}} \nc{\ecode}{\end{code}} \nc{\bsage}{\begin{sageblock}} \nc{\esage}{\end{sageblock}} %pic \nc{\pic}{\includegraphics} \nc{\svg}{\includesvg} \nc{\pica}{\includegraphics[width=100px,height=100px]} \nc{\picb}{\includegraphics[width=150px,height=150px]} \nc{\vs}{\vspace} \nc{\tbf}{\textbf} %arrow \nc{\upa}{\nearrow} \nc{\downa}{\searrow} \nc{\upw}{\rcurvearrowright} \nc{\downw}{\curvearrowright} \)

class subclass : public superclass{
 //code
};

class Shape{
    private:
        int width;
        int height;
    public:
        Shape(int w,int h):width{w},h{height}{}
};
class Rectangle : public Shape{
    public:
        int getArea(){return width*height;}
};

#include <iostream>
using namespace std;
int main(){
 Rectangle rec{5,6};
 cout<<getArea();
}