Why won't this compile?

[Dillinger4]

Compiler keeps complaining about <identifier> expected at 1st in the enum GearState.

class Transmission{
  public enum GearState{neutral,1st,2nd,3rd,4th,5th,6th};
  private int currentgear = GearState.neutral;

  public void setGear(GearState gs){
    currentgear = gs;
  }
  public GearState getNextGear(){
  switch(currentgear){
   case neutral: return GearState.neutral;
   case 1st: return GearState.1st;
   case 2nd: return GearState.2nd;
   case 3th: return GearState.3rd;
   case 4th: return GearState.4th;
   case 5th: return GearState.5th;
   case 6th return GearState.6th;
  }
 }
  public void printGears(){
   for(GearState gs: GearState.values()){
    System.out.println(gs);
   }
  }
 }
 public class Car {
  public static void main(String[] args){
   Transmission trans = new Transmission();
   System.out.println(trans.getNextGear());
   trans.setGear(Transmission.GearState.1st);
   System.out.println(trans.getNextGear());
  }
 }