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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <iostream>
#include<algorithm>
//#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb emplace_back
#define mp make_pair
#define MOD (int) 1e9+7
#define for0(i, n) for (int i = 0; i < n; i++)
#define ff first
#define ss second
#define endl "\n"
#define bits(n) __builtin_popcount(n)
#define ini(a, i) memset(a, i, sizeof(a))

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	ll t;
	// cin >> t;
	t  = 1;
	while (t--)
	{
		ll a, b, c;
		cin >> a >> b >> c;
		cout << (b / c) - ((a - 1) / c) << endl;
	}
	return 0;
}