Input (grade 13): The Itza Maya, Ko 'woj, and Yalain groups of Central Peten survived the "Classic Period Collapse" in small numbers and by 1250 reconstituted themselves to form competing city-states.
Output (grade 8): The Itza Maya, Ko 'woj, and Yalain groups of Central Peten survived the "Classic Period Collapse" in small numbers.