There are 20 2-cent coins and 15 5-cent coins. Use these coins to form a currency value of more than 0 yuan and no more than 0.5 yuan. How many different currency values are there?
有20枚2分硬币，15枚5分硬币，用这些硬币组成多于0元，不超过0.5元的币值，不同的币值有多少种．
<result>48</result>