Problem:
Score : 100 points

Problem Statement

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.

Sample Input 1

5

Sample Output 1

3

By printing the 1-st, 2-nd pages on the 1-st sheet, 3-rd and 4-th pages on the 2-nd sheet, and 5-th page on the 3-rd sheet, we can print all the data on 3 sheets of paper.

Sample Input 2

2

Sample Output 2

1

Sample Input 3

100

Sample Output 3

50

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io::{BufRead, BufReader};

fn main(){
    let n = read::<i32>()[0];
    let ans = n / 2 + n % 2;
    println!("{}",ans);
}

fn read<T>() -> Vec<T>
where
  T: std::str::FromStr,
  T::Err: std::fmt::Debug,
{
    let lines: Vec<T> =
        BufReader::new(std::io::stdin())
        .lines()
        .map(|l| l.unwrap().parse::<T>().unwrap())
        .collect();
    lines
}