#![allow(dead_code, deprecated, unused_variables, unused_mut)]
use std::ops::Mul;
#[derive(Debug, Eq, PartialEq)]
struct Rational {
    numerator: usize,
    denominator: usize,
}
impl Rational {
    fn new(numerator: usize, denominator: usize) -> Self {
        if denominator == 0 {
            panic!("Zero is an invalid denominator!");
        }
        let gcd = gcd(numerator, denominator);
        Self {
            numerator: numerator / gcd,
            denominator: denominator / gcd,
        }
    }
}
impl Mul for Rational {
    type Output = Self;
    fn mul(self, rhs: Self) -> Self {
        let numerator = self.numerator * rhs.numerator;
        let denominator = self.denominator * rhs.denominator;
        Self::new(numerator, denominator)
    }
}
fn gcd(x: usize, y: usize) -> usize {
    let mut x = x;
    let mut y = y;
    while y != 0 {
        let t = y;
        y = x % y;
        x = t;
    }
    x
}
fn main() {
    assert_eq!(Rational::new(1, 2), Rational::new(2, 4));
    assert_eq!(Rational::new(2, 3) * Rational::new(3, 4), Rational::new(1, 2));
}