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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scanf("%d", &n)
	fmt.Printf("%d\n", find(n))
}

func find(n int) int {
	var num int
	for i := 1; i <= n; i++ {
		if i%2 == 1 && divisorNumIs(i, 8) {
			num++
		}
	}
	return num
}

func divisorNumIs(n, divisor int) bool {
	life := divisor - 2
	for i := 2; i*i <= n; i++ {
		if n%i == 0 {
			if n/i == i {
				life--
			} else {
				life -= 2
			}
		}
		if life < 0 {
			break
		}
	}
	return life == 0
}