check: a.out
	@echo 'Output should be "1,2,3,4,5,6,7,8,9,10"'
	./a.out

a.out: x.o y.o
	gcc x.o y.o

x.o: x.c
	gcc -O -c x.c

y.o: y.c
	gcc -mflat -fpic -O -c y.c