There are two postage stamps with postage face value of 0.80 yuan and 1.20 yuan respectively, how many kinds of postage can be paid at most.
有邮资面值是0.80元和1.20元的邮票各两张，最多可以支付多少种邮资．
<gadget id="calculator">0.8 + 1.2</gadget>
<output>2</output>

<gadget id="calculator">2 + 6</gadget>
<output>8</output>

<result>8</result>