Problem:
Score : 100 points

Problem Statement

How many multiples of d are there among the integers between L and R (inclusive)?

Constraints

All values in input are integers.

1 \leq L \leq R \leq 100

1 \leq d \leq 100

Input

Input is given from Standard Input in the following format:

L R d

Output

Print the number of multiples of d among the integers between L and R (inclusive).

Sample Input 1

5 10 2

Sample Output 1

3

Among the integers between 5 and 10, there are three multiples of 2: 6, 8, and 10.

Sample Input 2

6 20 7

Sample Output 2

2

Among the integers between 6 and 20, there are two multiples of 7: 7 and 14.

Sample Input 3

1 100 1

Sample Output 3

100

Solution in C# (Mono-csc 3.5.0) (judge verdict: Accepted)

using System;
using System.Linq;

namespace AtCoder.Abc
{
    public class QuestionA
    {
        public static void Main(string[] args)
        {
            var sw = new System.IO.StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);

            // 整数配列の入力
            var inputLongArray = Console.ReadLine().Split(' ').Select(i => long.Parse(i)).ToArray();


            var result = 0;

            for (var i = inputLongArray[0]; i <= inputLongArray[1]; i++)
            {
                if (i % inputLongArray[2] == 0)
                {
                    result += 1;
                }
            }


            Console.WriteLine(result);

            Console.Out.Flush();
        }
    }
}