Search your library for a permanent card with converted mana cost X or less, put it onto the battlefield, then shuffle your library.
5/1/2009 A permanent card is an artifact, creature, enchantment, land, or planeswalker card.
5/1/2009 You may always find a permanent card with converted mana cost 0. (If X is 0, that’s all you can find.) Cards with no mana cost (such as land cards), cards with mana cost , and cards with mana cost all have converted mana cost 0.