Main {
{{
  public static void main(String args[]) throws Exception {
    EquationSystem s = EquationSystem.parse(System.in);
    System.out.println("done parsing");
    // ClassGraph cg = new ClassGraph(true, false);
    HashSet used = s.getUsedVars();
    Iterator it = used.iterator();
    System.out.println(" Used Variables");
    while (it.hasNext()){
			    Variable curvar = (Variable) it.next();
			    System.out.println();
			    curvar.print();
    }
    System.out.println();
    HashSet defined = s.getDefinedVars();
    System.out.println("done");
  }
}}
}