error[E0081]: discriminant value `3` already exists
  --> $DIR/E0081.rs:13:9
   |
LL |     P = 3,
   |         - first use of `3`
LL |     X = 3,
   |         ^ enum already has `3`

error: aborting due to previous error

If you want more information on this error, try using "rustc --explain E0081"