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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

namespace AtCoder.ABC106.B
{
    class Program
    {
        static void Main(string[] args)
        {
            // 入力値の検証は割愛
            var N = int.Parse(Console.ReadLine());

            var calculator = new Calculator();

            var answer = calculator.GetAnswers(N, divisorsCount: 8);

            Console.WriteLine(answer.Count());
        }
    }

    public class Calculator
    {
        public IEnumerable<int> GetAnswers(int max, int divisorsCount)
        {
            return Enumerable.Range(1, max).Where(i =>
            {
                return i % 2 == 1 && GetDivisors(i).Count() == divisorsCount;
            });
        }

        public IEnumerable<int> GetDivisors(int value)
        {
            return Enumerable.Range(1, value).Where(i => value % i == 0);
        }
    }
}