use  std::str::{FromStr};

fn main() {
	let weight = input::<i64>("Patient's weight (kg):");
	let time_passed = input::<i64>("How much time has passed from the previous dose (full hours): ");
	let total_dose = input::<i64>("The total dose for the last 24 hours (mg): ");
	if total_dose >= 4000{
		println!("You can't take another dose this day")
	} else {
		let next_dose = calculate_dose( weight, time_passed, total_dose);
		println!("The amount of Parasetamol to give to the patient: {}", next_dose)
	}
}

fn calculate_dose(weight: i64, time_passed: i64, total_dose: i64) -> i64{
	if time_passed < 6 {
	    0
	} else {
		let next_dose = weight * 15;
		if next_dose + total_dose > 4000 {
			4000 - total_dose
		} else {
		    next_dose
		}
	}
}

fn input<F>(prompt: &str) -> F where
   F: FromStr {
      use std::io::{stdin, self, Write};
      print!("{}", prompt);
      io::stdout().flush().unwrap();
      let mut guess = String::new();
      let _= stdin().read_line(&mut guess);
      let a = guess.to_string().trim().parse::<F>();
      match a {
            Ok(v) => v,
            Err(_) => panic!("Parse failed!")
      }
    }