A fish is divided into three parts: head, body and tail. If the fish tail weighs 4 kg, the weight of the fish head is equal to half of the fish body plus the weight of the fish tail, and the weight of the fish body is equal to the weight of the fish head plus the tail. Question: How much does this fish weigh?
一条鱼分为鱼头、鱼身、鱼尾三段．如果鱼尾重4千克，鱼头重量等于鱼身的一半加上鱼尾的重量，鱼身重量等于鱼头加鱼尾的重量．请问：这条鱼有多重？
<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">8 / (1/2)</gadget>
<output>16</output>

<gadget id="calculator">8 + 4 + 16 + 4</gadget>
<output>32</output>

<result>32</result>