Problems
The number of evens #2
The number of evens #2
Your program is given a natural number $n$. It must print the number of even natural numbers smaller than $n$.
\InputFile
A natural number $n$, does not exceed $10^{18}$.
\OutputFile
The answer to the problem.
Input example #1
7
Output example #1
3
Input example #2
6
Output example #2
2