Using 16 squares with sides of 1 cm to form a rectangle or a square, what is the shortest perimeter in centimeters?
用16个边长都是1厘米的正方形拼长方形或正方形，周长最短是多少厘米．
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>