Problems
Maximum Frequency Stack
Maximum Frequency Stack
Design a stack-like data structure to push elements to the stack and pop the most frequent element from the stack. The possible commands are:
\begin{itemize}
\item \textbf{push n} --- pushes an integer $n$ onto the top of the stack;
\item \textbf{pop} --- removes and prints the most frequent element in the stack. If there is a tie for the most frequent element, the element closest to the stack's top is removed and printed.
\end{itemize}
\InputFile
Each line contains a single command.
\OutputFile
For each \textbf{pop} command print on a separate line the corresponding result.
Input example #1
push 4 push 5 push 4 push 6 push 7 pop push 5 pop pop
Output example #1
4 5 7
Input example #2
push 5 push 3 push 1 push 3 push 9 pop pop pop pop pop
Output example #2
3 9 1 3 5