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 6): The maya Itza, Ko 'woj, and Yalain groups of Central Peten survived the "Classic Period Collapse" in small numbers. By 1250, they started to form competing city-states.