A column of numbers: 3, 5, 7, 9, 11... The sum of all the numbers in it is a two-digit number with the same two numbers. What is the last number in this column.
一列数：3、5、7、9、11…它的所有的数的和是一个两个数字相同的两位数，这列数的最后一个数是多少．
<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<result>19</result>