A and B have opened a passenger railway line, and there are 7 stations along the way. How many possible tickets should the railway department prepare for this railway?
甲、乙两地开通了一条客运铁路线，沿途共有7个车站，铁路部门共要为这条铁路准备多少种可能的车票？
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">7 * 6</gadget>
<output>42</output>

<result>42</result>