Task
           Time limit: 
1000 ms,
           
Memory limit: 
256 Mb
           Write a program for calculating 
\(y\) according to he formula:
\(\begin{equation*} y(x) = \begin{cases} 0 &\text{x = 0}\\ x^2-x-1 &\text{in other cases} \end{cases} \end{equation*}\)
Input: integer 
\(x\)
Output: \(y\)
Example