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 PHP (7.4.4) (judge verdict: Accepted)

<?php
$a = explode(" ", trim(fgets(STDIN)));
$n = 0;
for ($i = $a[0]; $i < $a[1]+1; $i++) {
    if ($i % $a[2] === 0) {
        $n++;
    }
}
echo $n . "\n";