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)

def s()
  gets().chomp
end
def i()
  gets.to_i
end
def li()
  gets.split.map(&:to_i)
end
def ili()
  n = gets.to_i
  as = gets.split.map(&:to_i)
  [n, as]
end
class Array
  def sum
    total = 0
    self.each do |item|
      total += item
    end
    total
  end
end

def eratosthenes(size)
  prime_list = []
  is_prime = Array.new(size, true)
  is_prime[0] = false
  is_prime[1] = false

  2.upto(size-1){|i|
    if is_prime[i]
      prime_list << i
      (2).upto((size.to_f/i).ceil-1){|j|
        is_prime[j*i] = false
      }
    end
  }
  [prime_list, is_prime]
end

def dijkstra(s, e, cost)
  size = cost.length
  if s==e
    return 0
  end
  dp = {}
  dp[s] = 0
  undefined_node = {}
  size.times{|i|
    if i != s
      undefined_node[i] = cost[s][i]
    end
  }
  while undefined_node.length != 0
    min = undefined_node.min_by{|_, v| v}
    stock = {}
    temp = undefined_node.clone
    temp.each{|k, v|
      if min[1] == v
        undefined_node.delete(k)
        if k == e
          return v
        end
        dp[k] = v
        stock[k] = v
      end
    }

    stock.each{|k, v|
      undefined_node.each{|k2, v2|
        undefined_node[k2] = v + cost[k][k2] < v2 ?  v + cost[k][k2] : v2
      }
    }
  end
end

def get_bits(len)
  res =  []
  (2**len).times{|i|
    res << i.to_s(2).rjust(len, '0')
  }
  res
end

def yakusu(n)
  count = 0
  1.upto(n){|i|
    if n%i == 0
      count +=1
    end
  }
  count
end
n=i()

res = 0
(1+n).times{|i|
  if yakusu(i)==8 && i%2 == 1
    res += 1
  end
}

puts res