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 Rust (1.42.0) (judge verdict: Accepted)

use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        n: usize
    }

    let mut ans = 0;
    for i in 1..=n {
        if i % 2 == 0 {
            continue;
        }

        let mut div_num = 0;
        for k in 1..=(i as f64).sqrt() as usize {
            if i % k == 0 {
                div_num += 1;
                if k != i / k {
                    div_num += 1;
                }
            }
        }
        if div_num == 8 {
            ans += 1;
        }
    }
    println!("{}", ans);
}