On one side of a 100-meter-long road, 20 trees were planted from the beginning to the end, and 2 potted flowers were placed between every two trees. How many potted flowers were placed in total?
在一条长100米的马路一边从头至尾栽了20棵树，每两棵树之间又摆了2盆花，一共摆了几盆花？
<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<gadget id="calculator">19 * 2</gadget>
<output>38</output>

<result>38</result>