shoe factory produces 4,500 pairs of sandals in 3 days, of which 1,200 pairs are plastic sandals, and the rest are leather sandals. How many more pairs of leather sandals than plastic sandals?
制鞋厂3天生产4500双凉鞋，其中1200双是塑料凉鞋，其余是皮凉鞋，皮凉鞋比塑料凉鞋多多少双？
<gadget id="calculator">4_500 - 1_200 - 1_200</gadget>
<output>2_100</output>

<result>2_100</result>