I would like that every time I enter the right property name "title" of my class children and confirm, the available quantity of that title (initially set to 10), decreases.

I'm going crazy, what can I do?

class Catalog{
    #initial = 10;
    constructor(title){
        this.title = title;
    };
    get initial(){
        return this.#initial;
    };

    set initial(value){
        return this.#initial = this.initial - value;
    };
    
    amounts(){
        let search = prompt("Cerca il tuo dvd", "");
        let confirmed = confirm("Vuoi confermare l'acquisto?");
        
        
        if(search === this.title && confirmed){
          return this.initial - 1;    // ?????????         
        } 
        
    };
    

}



class Matrix extends Catalog{
    constructor(title){
        super(title);
        this.title = title;
    };
   
    
}

const x = new Matrix("Matrix");

console.log(x.amounts())