How many ways are there to add two different integers from 1 to 10 each time, and the sum is not less than 12?
从1～10中每次取两个不同的整数相加，和不小于12的共有多少种取法．
<gadget id="calculator">1 + 2 + 3 + 4 + 4 + 3 + 2 + 1</gadget>
<output>20</output>

<result>20</result>