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.IO;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Numerics;

namespace alsing2020
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
            if (File.Exists("input.txt"))
            {
                Console.SetIn(new StreamReader("input.txt"));
            }
            solve_alsing2020A();
            Console.Out.Flush();
        }
        public static void solve_alsing2020()
        {
        }

        public static void solve_alsing2020B()
        {
        }

        public static void solve_alsing2020A()
        {
            int[] lrd = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
            int cnt = 0;
            for (int i = lrd[0]; i <= lrd[1]; i++)
            {
                if (i % lrd[2] == 0)
                {
                    cnt++;
                }
            }
            Console.WriteLine(cnt);
        }
    }
}