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# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.IO.Compression;
using System.Linq;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Text;
using System.Text.RegularExpressions;
using Console = System.Console;

namespace Atcoder
{
    
    class Program
    {
        private const long COMDIV = 1000000007;

        static void Main(string[] args)
        {
            var LRd = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int ret = 0;
            for (int i = LRd[0]; i <= LRd[1]; i++)
            {
                if (i % LRd[2] == 0)
                {
                    ret++;
                }
            }

            Console.WriteLine(ret);
        }
    }
}