Eight representative teams from Yuhua area participated in the "Yuhua Cup" basketball game, which was divided into two stages. The first stage: 8 teams are divided into two groups, and each group performs a single round-robin, and the top two teams are determined to participate in the second stage. The second stage: The four teams will be single-eliminated to determine the champion and runner-up. How many games will it take to determine the champion and runner-up?
玉华地区8个代表队参加"玉华杯"篮球比赛，比赛分两个阶段．第一阶段：8个队分为两组，每组进行单循环，决出前两名参加第二阶段比赛．第二阶段：四个队进行单淘汰制，决出冠亚军．决出冠亚军共需多少场比赛？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

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

<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<result>15</result>