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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using static System.Math;
using static System.Console;
using static exMath;
using static exReadLine;


class Program
{
    static void Main(string[] args)
    {
        int N;
        intReadLine(out N);
        WriteLine(N / 2 + N % 2);
        //ReadLine();
    }
}

static class exReadLine
{
    public static void intReadLine(out int a)
    {
        a = int.Parse(ReadLine());
    }
    public static void intReadLine(out int a, out int b)
    {
        int[] input = ReadLine().Split().Select(int.Parse).ToArray();
        a = input[0];
        b = input[1];
    }
    public static void intReadLine(out int a, out int b, out int c)
    {
        int[] input = ReadLine().Split().Select(int.Parse).ToArray();
        a = input[0];
        b = input[1];
        c = input[2];
    }
    public static void intReadLine(out int a, out int b, out int c, out int d)
    {
        int[] input = ReadLine().Split().Select(int.Parse).ToArray();
        a = input[0];
        b = input[1];
        c = input[2];
        d = input[3];
    }

    public static void longReadLine(out long a)
    {
        a = long.Parse(ReadLine());
    }
    public static void longReadLine(out long a, out long b)
    {
        long[] input = ReadLine().Split().Select(long.Parse).ToArray();
        a = input[0];
        b = input[1];
    }
    public static void longReadLine(out long a, out long b, out long c)
    {
        long[] input = ReadLine().Split().Select(long.Parse).ToArray();
        a = input[0];
        b = input[1];
        c = input[2];
    }
    public static void longReadLine(out long a, out long b, out long c, out long d)
    {
        long[] input = ReadLine().Split().Select(long.Parse).ToArray();
        a = input[0];
        b = input[1];
        c = input[2];
        d = input[3];
    }
    
    public static int[] intArrayReadLine()
    {
        return ReadLine().Split().Select(int.Parse).ToArray();
    }

    public static long[] longArrayReadLine()
    {
        return ReadLine().Split().Select(long.Parse).ToArray();
    }

    public static List<int> intListReadLine()
    {
        return ReadLine().Split().Select(int.Parse).ToList();
    }

    public static List<long> longListReadLine()
    {
        return ReadLine().Split().Select(long.Parse).ToList();
    }
}

static class exMath
{
    // 最大公約数
    public static int Gcd(int a, int b)
    {
        if (a < b) return Gcd(b, a);
        while (b != 0)
        {
            var r = a % b;
            a = b;
            b = r;
        }
        return a;
    }
    public static long Gcd(long a, long b)
    {
        if (a < b) return Gcd(b, a);
        while (b != 0)
        {
            var r = a % b;
            a = b;
            b = r;
        }
        return a;
    }

    // 最小公倍数
    public static long Lcm(int a, int b)
    {
        return BigMul(a, b) / Gcd(a, b);
    }
    public static long Lcm(long a, long b)
    {
        return a * b / Gcd(a, b);
    }
}