fn main() {

  let day = 4;

​

  match day {

    1 => println!("Monday"),

    2 => println!("Tuesday"),

    3 => println!("Wednesday"),

    4 => println!("Thursday"),

    5 => println!("Friday"),

    6 => println!("Saturday"),

    7 => println!("Sunday"),

    _ => println!("Invalid day."),

  }

}