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 Ruby (2.3.3) (judge verdict: Runtime Error)

list = []
(1..3).each do |i|
    line = gets.chomp.split(" ")
    (0..2).each do |k|
        list.push(line[k].to_i)
    end
end

count = gets.chomp.to_i

list2 = []
(1..count).each do |i|
    num = gets.chomp.to_i
    if list.include?(num)
        list2.push(list.index(num))
    end
end

if list2.include?(0) && list2.include?(1) && list2.include?(2)
    puts "Yes"
elsif list2.include?(3) && list2.include?(4) && list2.include?(5)
    puts "Yes"
elsif list2.include?(6) && list2.include?(7) && list2.include?(8)
    puts "Yes"
elsif list2.include?(0) && list2.include?(3) && list2.include?(6)
    puts "Yes"
elsif list2.include?(1) && list2.include?(4) && list2.include?(7)
    puts "Yes"
elsif list2.include?(2) && list2.include?(5) && list2.include?(8)
    puts "Yes"
elsif list2.include?(0) && list2.include?(4) && list2.include?(8)
    puts "Yes"
elsif list2.include?(2) && list2.include?(4) && list2.include?(6)
    puts "Yes"
else
    puts "No"
end