Mana Quarry

Mana Quarry comes into play with
5 depletion counters on it.
{4}: Regenerate.
{t}: add one mana of any one color.
{3}: add one depletion counter on this card.
{t}: add X mana of any one color, where X is
equal to the number of depletion counters on
this card, remove all depletion counters.