There are one yuan, two yuan, five yuan, ten yuan, fifty yuan, and one hundred yuan banknotes in your pocket. If you take out 4 of them each time and calculate their amount of money, how many different amounts of money are there?
你的口袋里有一元、二元、五元、十元、五十元、一百元的纸币各一张．如果每次取出其中的4张计算它们的钱数，共有多少种不同的钱数．
<result>15</result>