DEPENDENT because what letters are available to pick second DEPENDS on what was
picked first.

For instance, if you picked R first, then the second event is AFFECTED because
R is not available to be picked for the second event.  

[Note:  If the R were replaced after picking it the first time, then the events
would be independent, because what was picked the first time would have no
effect on what was picked the second time, but since it isn't replaced, the
second event DEPENDS on what was picked the first time.]

Edwin