At the International Snow Sculpture Championships in Colorado on January 27, people will carve the white stuff into art．Planning begins months before the first snow falls．Teams submit applications and sketches of their sculptures in July．Then, a panel of judges chooses 14 teams for the championship.
The rules are : Electric tools are not allowed．Teams carve snow with everything but the results are not entirely in the sculptors' hands．'If it is extremely sunny and warm', DeWall, the competition's director of public relations, explained, 'we will erect old sail from sail boats into the air to block the sun from melting the sculptures'．If it snows, she continued, teams have to work extra hard to sc(刮掉) the new snow off their work.
The judges look for creativity, technical skill, and overall impact on the viewer．The winner does not receive any money．'There is no cash prize because the began with the concept of global camaraderie(情谊)', DeWall explained．Instead of focusing on money, she continued, 'winners revel(纵情) in the friendship, the art, and the hard work'.
What does the phrase 'white stuff' in the first paragraph refer to?