Mr. Li forgot the power-on password of his computer, but he remembered that the password was a four-digit number consisting of two 2, one 6, and one 9, so he used these four numbers to randomly arrange a four-digit number and input it into the computer to try. Then he wants to turn on the computer, how many times does he need to try at most?
李先生忘记了自己电脑的开机密码，但记得密码是由两个2，一个6，一个9组成的四位数，于是，他用这四个数字随意排成一个四位数输入电脑尝试．那么他要打开电脑，最多需尝试多少次．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 * 3 * 2 * (1/2)</gadget>
<output>12</output>

<result>12</result>