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 (1.15.1) (judge verdict: Accepted)

fn input<T: std::str::FromStr>() -> T {
    let stdin = std::io::stdin();
    let s: String = std::io::Read::bytes(stdin.lock())
        .map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    s.parse().ok().expect("error")
}

fn count_divisor(n: &u32) -> usize {
    (1..n + 1).filter(|i| n % i == 0).count()
}

fn main() {
    let n: u32 = input();
    println!(
        "{}",
        (1..n + 1)
            .filter(|i| i % 2 == 1)
            .filter(|i| count_divisor(i) == 8)
            .count()
    );
}