A key can open a lock, and the existing 3 keys and 3 locks are mixed up. At least how many times to try to open the lock and the key can be matched.
一把钥匙开一把锁，现有3把钥匙和3把锁弄混了，至少试开多少次，就能把锁和钥匙配起来．
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<result>3</result>