const DAYS: [u64; 12] = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

const fn get_sum_of_digits(mut n: u64) -> u64 {
    let mut sum = 0;

    while n > 0 {
        sum += n % 10;
        n /= 10;
    }

    sum
}

fn main() {
    let answer = DAYS
        .iter()
        .enumerate()
        .flat_map(|(m, &n)| (1..=n).map(|d| (m as u64 + 1, d)).collect::<Vec<_>>())
        .filter(|&(m, d)| get_sum_of_digits(d) == m)
        .count();

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