The sum of 3 consecutive natural numbers is 57, what is the smallest number among them
3个连续自然数的和是57，它们最小的一个数是多少
<gadget id="calculator">57 / 3</gadget>
<output>19</output>

<gadget id="calculator">19 - 1</gadget>
<output>18</output>

<result>18</result>