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 Ruby (2.7.1) (judge verdict: Accepted)

line = gets.chomp.split(" ").map(&:to_i)
# line = [6, 20 , 7]

l = line[0]
# l = 6
r = line[1]
# r = 20
d = line[2]


d_count = 0

(l..r).each do |num|
  if num % d === 0
    d_count += 1
  end
end

puts d_count