\begin{minipage}[t]{8in}
\begin{tabular}{ll}
Stack$<$Item$>$  & s;
\end{tabular}\\
 
 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Create an empty \Stack. $O(1)$\end{minipage}
\end{minipage}
\vspace{0.2in}


\begin{minipage}[t]{8in}
\begin{tabular}{ll}
Stack$<$Item$>$  & s2(s);
\end{tabular}\\
 
 \parbox[b]{2in} \ \ 
\begin{minipage}[t]{4in}Create an empty \Stack\ and initialize it with the
			 elements of $s$ such that the elements will be popped
			 in the same order. $O(n)$\end{minipage}
\end{minipage}
\vspace{0.2in}

