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 (2.3.3) (judge verdict: Accepted)

n=gets.chomp.to_i

ans = 0
2.upto(n) do |m|
    next if m%2==0
    pf = Hash.new(0)
    i=2
    mm=m
    while m>=i**2
        if mm%i==0
            pf[i]+=1
            mm/=i
        else
            i+=1
        end
    end
    c=1
    pf.each do |k,v|
        c*=(v+1)
    end
    if c == 8
        ans +=1
    end
end

puts ans