JAVAC=javac

# target: dependencies
#	command 1
#	command 2
# 	...

run: HelloWorld.class
	java HelloWorld

HelloWorld.class: HelloWorld.java
	$(JAVAC) HelloWorld.java

HelloWorld.java:
	echo "class HelloWorld { public static void main(String[] args) { System.out.println(1); }}" > HelloWorld.java

clean:
	rm -f HelloWorld.*