Three people eat buns. A said: "I ate 2." B said: "If I eat one less, it will be three times as much as C." C said: "If I eat one more, it will be twice as much as A." It costs 15 yuan, so how much is the price of a small bread.
三个人吃小面包．甲说："我吃了2个．"乙说："如果我少吃一个就是丙的3倍．"丙说："如果我多吃1个就是甲的2倍．"三人吃小面包一共花了15元，那么一个小面包的价格是多少元．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">2 + 9 + 1 + 3</gadget>
<output>15</output>

<gadget id="calculator">15 / 15</gadget>
<output>1</output>

<result>1</result>