For an 84-meter log, paint every 4-meter point with red and every 3-meter point with white, and then saw off from these red and white points. How many sections were sawed in total.
一根84米的圆木，每隔4米的这一点涂上红色，每隔3米的这一点涂上白色，然后从这些红、白点处锯断．一共锯成了多少段．
<gadget id="calculator">84 / 4</gadget>
<output>21</output>

<gadget id="calculator">21 - 1</gadget>
<output>20</output>

<gadget id="calculator">84 / 3</gadget>
<output>28</output>

<gadget id="calculator">28 - 1</gadget>
<output>27</output>

<gadget id="calculator">84 / 12</gadget>
<output>7</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">27 - 6</gadget>
<output>21</output>

<gadget id="calculator">20 + 21</gadget>
<output>41</output>

<gadget id="calculator">41 + 1</gadget>
<output>42</output>

<result>42</result>