#abc157a. [abc157_a]Duplex Printing
[abc157_a]Duplex Printing
Problem Statement
Takahashi wants to print a document with pages double-sided, where two pages of data can be printed on one sheet of paper.
At least how many sheets of paper does he need?
Constraints
- is an integer.
Input
Input is given from Standard Input in the following format:
Output
Print the answer.
Sample Input 1
5
Sample Output 1
3
By printing the -st, -nd pages on the -st sheet, -rd and -th pages on the -nd sheet, and -th page on the -rd sheet, we can print all the data on sheets of paper.
Sample Input 2
2
Sample Output 2
1
Sample Input 3
100
Sample Output 3
50