Yi Ling's birthday is the fourth Friday in January. Now we know that the sum of all Fridays in January is 80. May I ask when is her birthday?
依玲小朋友的生日是一月的第四个星期五．现在知道一月份所有星期五的日期之和为80．请问她的生日是几日？
<gadget id="calculator">80 - 7 - 14 - 21 - 28</gadget>
<output>10</output>

<gadget id="calculator">1 + 1 + 1 + 1 + 1</gadget>
<output>5</output>

<gadget id="calculator">10 / 5</gadget>
<output>2</output>

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<gadget id="calculator">2 + 21</gadget>
<output>23</output>

<result>23</result>