What is the sum of the perimeters of all squares whose perimeter is not more than 100 (including 100) and whose side lengths are natural numbers.
周长不超过100(包括100)，且边长为自然数的所有正方形的周长之和是多少．
<gadget id="calculator">1 + 25</gadget>
<output>26</output>

<gadget id="calculator">25 / 2</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">26 * (25/2) * 4</gadget>
<output>1_300</output>

<result>1_300</result>