a.out: main.o calendar.o event.o datetime.o
	g++ main.o calendar.o event.o datetime.o

main.o: main.cc main.h calendar.h event.h datetime.h
	g++ -c main.cc

calendar.o: calendar.cc calendar.h
	g++ -c calendar.cc

event.o: event.cc event.h
	g++ -c event.cc

datetime.o: datetime.cc datetime.h
	g++ -c datetime.cc

clean:
	rm -f *.o core a.out