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 ncd(x: i32) -> i32 {
    let mut num = 0;
    for i in 1..x + 1 {
        if x % i == 0 {
            num += 1;
        }
    }
    num
}

fn main() {
    let n: i32 = read_line();
    let mut ans = 0;
    for i in 1..n + 1 {
        if i % 2 == 1 && ncd(i) == 8 {
            ans += 1;
        }
    }

    println!("{}", ans);
}

fn read_line<T: std::str::FromStr>() -> T {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).unwrap();
    buf.trim().parse().ok().unwrap()
}