计算n元钱硬币有多少种表达方式。例如，对于1元，可以使用1元钱完成，也可以使用两个5角完成。可用于三种不同货币，每种货币提供不同面额。编写程序计算出每一种组合方式。(How many expressions are there to calculate n dollar coins? For example, for 1 yuan, 1 yuan can be used and two 5 corners can be used. It can be used in three different currencies, each of which provides different denominations. Write programs to calculate each combination.)