The number of 4 more than 4 times of a number is 4 times of 40, find this number.
比一个数的4倍多4的数是40的4倍，求这个数．
<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<gadget id="calculator">160 - 4</gadget>
<output>156</output>

<gadget id="calculator">156 / 4</gadget>
<output>39</output>

<result>39</result>