There are 20 piles of stones, each with 100 stones. You can choose one pile for each operation, and take 1 stone from each of the other 19 piles, add all 19 stones to the selected pile of stones, and you can continue the above operation. After no more than 50 operations, a certain pile of stones has 66 stones, and another pile of stones has between 170 and 200 stones. What is the exact number of stones in this pile?
有20堆石子，每堆100个．每次操作都可任选一堆，而从其它19堆中各取1个石子，将19个石子全部都加入所选的这堆石子中，您可以继续以上的操作．经过不超过50次的操作之后，其中某一堆石子有66个石子，此时另有一堆石子的数量介于170和200个之间．请问这堆石子的确切数量是多少个？
<gadget id="calculator">20 * 6</gadget>
<output>120</output>

<gadget id="calculator">66 + 120</gadget>
<output>186</output>

<result>186</result>