class Person:
    def __init__(self, navn, alder):
        self._navn = navn
        self._alder = alder
    
    def doble_alder(self):
        self._alder = self._alder * 2
    
    def hent_alder(self):
        return self._alder
    
    def alder_som_maaneder(self):
        return self._alder * 12
    
    def bursdag(self):
        self._alder += 1
    
    def sett_alder(self, ny_alder):
        self._alder = ny_alder
    
p1 = Person("Anne", 3)
p2 = p1
p3 = Person("Lisa", 5)
p4 = p3
p1.doble_alder()

print("-------Oppg. 1: Hva skrives ut?-------")
print(p1.hent_alder())
print(p2.hent_alder())
print(p3.alder_som_maaneder())
print(p4.hent_alder())

print("\n-------Oppg. 2: Hva skrives ut?-------")
far = Person("Gjert", 48)
trener = far
trener.bursdag()
print(far.hent_alder())

print("\n-------Oppg. 3: Hva skrives ut?-------")
trener.sett_alder(60)
print(far.hent_alder())

print("\n-------Oppg. 4: Hva skrives ut?-------")
trener.sett_alder(48)
trener = Person("Tone", 66)
print(far.hent_alder())

print("\n-------Oppg. 5: Hva skrives ut?-------")
def feiring(p):
    p.bursdag()
    
feiring(far)
print(far.hent_alder())