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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp62 {
    class Program {
        static void Main(string[] args) {
            int N = int.Parse(Console.ReadLine());

            int type_A = 0;

            //〇×〇×〇×△型を探す
            for (int k = 1; k <= N; k += 2) {
                for (int i = 1; i * i * i <= k; i++) {
                    if (!isPrime(i)) {
                        continue;
                    }
                    if (N % i == 0 && k % (i * i) == 0 && k % (i * i * i) == 0 && k / (i * i * i) != i) {
                        if (isPrime(k / (i * i * i))) {
                            Console.WriteLine("(k, i) = " + k + " " + i);
                            type_A++;
                        }
                    }
                }
            }

            int type_B = 0;

            //〇×△×◇型を探す
            for (int i = 1; i * (i + 1) * (i + 2) <= N; i += 2) {
                for (int j = i + 2; i * i * j <= N; j += 2) {
                    for (int k = j + 2; i * j * k <= N; k += 2) {
                        if (isPrime(i) && isPrime(j) && isPrime(k) && i * j * k <= N) {
                            type_B++;
                        }
                    }
                }
            }

            Console.WriteLine(type_A + type_B);
        }

        //素数かどうかを返す
        static bool isPrime(int N) {
            if (N == 1) {
                return false;
            }

            if (N == 2 || N == 3) {
                return true;
            }

            for (int i = 2; i * i <= N; i++) {
                if (N % i == 0) {
                    return false;
                }
            }

            return true;
        }
    }
}