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<cmath>
#include<cstring>
#include<map>
#include<stack>
#include<queue>
#include<set>
using namespace std;
typedef long long ll;
const ll mod = 1e9+7;
int main(){
	ll x,y,z;
	cin>>x>>y>>z;
	ll i,j;
	ll s=0;
	for(i=x;i<=y;i++)
		if(i%z==0)
			s++;
	cout<<s<<endl;
}