Everyone knows that a normal cat has 18 claws, 5 claws on each front leg and 4 claws on each hind leg. 4 disabled cats were adopted in the "House for Protection of Disabled Animals" in a certain city. Each cat lost a leg, but each cat lost a different leg. How many claws do these 4 disabled cats have? ．
大家都知道，一只正常的猫有18个爪，每条前腿有5个爪，每条后腿有4个爪．在某市的"保护伤残动物之家"收养了4只伤残猫，每只猫都失去了一只腿，但是每只猫失去的腿都不相同，这4只伤残猫共有多少爪．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<result>54</result>