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 divisor(n)
  res = []
  (1..Math.sqrt(n)).each do |i|
    if (n % i).zero?
      res << i
      res << n/i
    end
  end
  res.sort
end
N = gets.to_i
m = 1
ans = 0
while m <= N
  d = divisor m
  ans += 1 if d.length == 8
  m += 2
end
puts ans