Duelists' Convocation International (MB2) (293)

When Duelists' Convocation International enters the battlefield, choose a 10-digit number at random and write it down.
Whenever you play a land or cast a spell, if it shares a mana value with one or more uncrossed digits in the chosen number, cross out one of those digits and draw a card. Then if all ten digits are crossed out, you win the game.