void main() {
    boolean hasTicket = true;
    int age = 15;

    if (hasTicket) {
        if (age >= 13) {
            IO.println("Enjoy the show.");
        } else {
            IO.println("You need an adult with you.");
        }
    } else {
        IO.println("Please buy a ticket first.");
    }
}

// From Groundwork, chapter 4 (ch04-making-decisions), box 7.
// This example is from Groundwork, licensed CC BY-NC-SA 4.0.
// Run with: java ch04_07.java