class Person {
	constructor(name, surname) {
		this.name = name;
		this.surname = surname;
	}

	getFullName() {
		return this.name + " " + this.surname;
	}
}


class Developer extends Person {
	constructor(name, surname, knownLanguage) {
	  super(name, surname);
		this. knownLanguage = knownLanguage;
	}

	displayCompetency() {
		console.log(super.getFullName() + " zna " + this.knownLanguage);
	}
}