There are 50 3-yuan stamps and 30 5-yuan stamps. How many different postages can be formed by using these stamps?
有50张3元邮票和30张5元邮票，用这些邮票能组成不同邮资有多少种．
<gadget id="calculator">300 - 8</gadget>
<output>292</output>

<result>292</result>