The elder brother and the younger brother share 15 pieces of chocolate, and the younger brother's chocolate is 1 piece less than the elder brother's three times. How many pieces of chocolate did the older brother and the younger brother originally have?
哥哥和弟弟共有巧克力15块，弟弟的巧克力比哥哥的3倍少1块，哥哥、弟弟原来各有多少块巧克力？
<gadget id="calculator">1 + 15</gadget>
<output>16</output>

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

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">15 - 4</gadget>
<output>11</output>

<result>11</result>