对给出的句子判断其主题,以{"LABEL": label}的格式作答。短文以sentence:<>格式给出,可选择的类别有: story, culture, entertainment, sports, finance, house, car, edu, tech, military, travel, world, stock, agriculture, game.
sentence:<武术大师教如何赤手空拳夺白刃，是真的吗，正能做到空手夺刀吗？>
{"LABEL": sports}