There are 99 single rooms, and 100 travelers stay in them. 99 of these 100 travelers stay at the same time at the same time. The administrator assigns some keys to each person. He wants everyone to be able to stay without asking others to borrow keys. Ask him at least how many keys are needed in total?
有99个单人间，有100个旅客入住，这100名旅客每次有99个人同时入住，管理员给每人配了一些钥匙，他想让每人都能入住，且不用找别人借钥匙，问他至少一共需要配多少把钥匙？
<gadget id="calculator">99 * 2</gadget>
<output>198</output>

<result>198</result>