Takahashi wants to print a document with N 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

• N is an integer.
• $1 \leq N \leq 100$

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer.

Examples

Input

5

Output

3

Input

2

Output

1

Input

100

Output

50

见题面

见题面