Problem:
Score: 200 points

Problem Statement

The number 105 is quite special - it is odd but still it has eight divisors.
Now, your task is this: how many odd numbers with exactly eight positive divisors are there between 1 and N (inclusive)?

Constraints

N is an integer between 1 and 200 (inclusive).

Input

Input is given from Standard Input in the following format:

N

Output

Print the count.

Sample Input 1

105

Sample Output 1

1

Among the numbers between 1 and 105, the only number that is odd and has exactly eight divisors is 105.

Sample Input 2

7

Sample Output 2

0

1 has one divisor. 3, 5 and 7 are all prime and have two divisors. Thus, there is no number that satisfies the condition.

Solution in Ruby (2.7.1) (judge verdict: Accepted)

def divisors(n)
  b = Array.new
  for i in 1..((n**0.5))
    if n % i == 0
      b.push(i)
    end
  end
  len = b.length
  len.times{|i|
    if n/b[len-1-i] != b[len-1-i]
      b.push(n/b[len-1-i])
    end
  }
  b
end

n = gets.to_i
sum = 0
1.upto(n) do |i|
  sum += 1 if divisors(i).length == 8 && i&1 == 1
end
puts sum