On both sides of a 420-meter-long road, from one end to the other, a tree is planted every 6 meters. In order to celebrate the 100th anniversary of the Revolution of 1911 this year, two trees were replanted between every two trees. How many trees are there on both sides of this road now?
在一条长420米的公路两边，从一端到另一端，每隔6米种一棵树．今年为了庆贺辛亥革命一百周年，又在每两棵间补种2棵，现在这条公路两旁共有多少棵树？
<gadget id="calculator">420 / 6</gadget>
<output>70</output>

<gadget id="calculator">70 + 1</gadget>
<output>71</output>

<gadget id="calculator">71 * 2</gadget>
<output>142</output>

<gadget id="calculator">70 * 2</gadget>
<output>140</output>

<gadget id="calculator">140 * 2</gadget>
<output>280</output>

<gadget id="calculator">142 + 280</gadget>
<output>422</output>

<result>422</result>