The sum of four consecutive natural numbers is 54. What is the smallest of these four numbers?
四个连续自然数的和是54，这四个数中最小是多少．
<gadget id="calculator">54 - 1 - 2 - 3</gadget>
<output>48</output>

<gadget id="calculator">1 + 1 + 1 + 1</gadget>
<output>4</output>

<gadget id="calculator">48 / 4</gadget>
<output>12</output>

<result>12</result>