A box of chocolates has 3 numbers of 3 or 4 numbers of 4 and there is only 1 piece left. What is the minimum number of chocolates in this box?
一盒巧克力3个3个的数或4个4个的数都剩1粒，这盒巧克力至少有多少粒．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">12 + 1</gadget>
<output>13</output>

<result>13</result>