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-csc 3.5.0) (judge verdict: Accepted)

using System;
using System.Numerics;

namespace study11
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            int caunto = 0;
            int ans = 0;
            for (int a = 1; a <= N; a+=2)
            {
                caunto = 0;
                for (int b = 1; b <= a; b++)
                {
                    if (a % b == 0) caunto++;                    
                }
                if (caunto == 8) ans++;
            }
            Console.WriteLine(ans);

        }
    }
}