The sum of three consecutive natural numbers is 42. What is the smallest of these three natural numbers?
三个连续自然数的和是42，这三个自然数中最小的是多少．
<gadget id="calculator">42 / 3</gadget>
<output>14</output>

<gadget id="calculator">14 - 1</gadget>
<output>13</output>

<result>13</result>