Now there are several pieces of chess pieces, they can just be arranged into a 4-layer hollow square matrix with 10 pieces on each side of the outer layer, so what is the total number of these pieces? How many chess pieces are there in the outermost layer?
今有棋子若干枚，它们恰好可以排成一个外层每边10枚棋子的4层空心方阵，那么这些棋子的总数是多少？最外层共有棋子多少枚．
<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">40 - 4</gadget>
<output>36</output>

<result>36</result>