There are 2 small sticks of 3 cm, 7 cm, and 15 cm each. Choose 3 small sticks to form a triangle. What is the shortest circumference in centimeters?
有3厘米、7厘米、15厘米的小棒各2根，选其中的3根小棒围成三角形，周长最短的是多少厘米．
<gadget id="calculator">3 + 7 + 7</gadget>
<output>17</output>

<result>17</result>