To celebrate the National Day, students origami cranes. Xiaoli folded 30 cranes, if Xiaoli took out (1/30) of the paper cranes folded by Xiaodong and gave them to Xiaodong, the number of cranes folded by the two would be equal. How many did Xiaodong break?
为庆祝国庆，同学们折纸鹤．小丽折了30只，如果从小丽折的纸鹤中拿出(1/30)给小冬，则两人折的只数相等．小冬折了多少只．
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 - (1/30) - (1/30)</gadget>
<output>14/15 = around 0.933333</output>

<gadget id="calculator">30 * (14/15)</gadget>
<output>28</output>

<result>28</result>