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: Wrong Answer)

n = gets.to_i

res = []
(1..Math.sqrt(n).to_i).each do |x|
  (1..Math.sqrt(n).to_i).each do |y|
    (1..Math.sqrt(n).to_i).each do |z|
      cal = (x**x) + (y**y) + (z**z) + (x * y) + (y * z) + (z * x)
      res << cal
    end
  end
end
n_res = res.select { |r| r <= n }

(1..n).each do |i|
  puts n_res.count(i)
end