The telephone number of a certain county is a seven-digit number, and the first three digits are known to be a fixed number 610, so how many telephones can be installed in the county at most.
某县的电话号码是一个七位数，已知前三位数是固定数610，那么该县最多可安装电话多少部部．
<gadget id="calculator">10 * 10 * 10 * 10</gadget>
<output>10_000</output>

<result>10_000</result>