Xiaojun wants to form a triangle with three small sticks whose length is a whole centimeter. There is already a small stick of 9 cm and a small stick of 15 cm. What is the shortest centimeter of the third small stick?
小军想用三根长度是整厘米数的小棒围成三角形，已经有一根9厘米和一根15厘米的小棒，那么第三根小棒最短是多少厘米．
<gadget id="calculator">15 - 9</gadget>
<output>6</output>

<result>6</result>