Main {
{{
  static ClassGraph cg;
  static public void main(String args[]) throws Exception {
  CSP cs = CSP.parse(System.in);
  ClassGraph cgc = new ClassGraph(true, false);
  cg = new ClassGraph(cgc,
          "from CSP bypassing -> *,tail,* to *");
  cs.process();
  }
}}
}

CSP {
{{
void process(){
  ForcedVisitor fV = new ForcedVisitor();
  Main.cg.traverse(this,"from CSP to Variable", fV);
  }
}}
}

ForcedVisitor {
{{
  private int relationNumber;
  private int variablePosition;
  private boolean forced;
  public void before(Constraint c){
    variablePosition=1;
    forced=false;
    relationNumber=c.get_relationNumber();
  }
  public void before(Variable v){
    if (!forced) {
      if (Relation.forced(relationNumber,variablePosition)!=-1){
        System.out.println(relationNumber);
	forced = true;
      } else variablePosition++;
    }
  }
}}
}
Relation {
{{
  static int forced( int r , int v ){return 1;}
}}
}