Master Li wants to surround two iron wires of the same length into a cuboid and a cube frame respectively. It is known that the length of the cuboid frame is 10 cm, the width is 6 cm, and the height is 5 cm. What is the length of the sides of the cube frame?
李师傅要把两根同样长的铁丝分别围成一个长方体和一个正方体框架，已知长方体框架长是10厘米，宽是6厘米，高是5厘米．正方体框架的棱长是多少厘米？
<gadget id="calculator">10 + 6 + 5</gadget>
<output>21</output>

<gadget id="calculator">4 / 12</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">21 * (1/3)</gadget>
<output>7</output>

<result>7</result>