When Scrub Flats enters the battlefield, sacrifice it unless you pay .
: Add or to your mana pool.
: Add to your mana pool. Put Scrub Flats on top of your library.
At the beginning of your upkeep, you may gain 1 life.
.
: Add or 
to your mana pool.: Add 
to your mana pool. Put Scrub Flats on top of your library.
