piggyBank $(25$ points$)$

Implement a function piggyBank that represents a piggy bank and determines its value. Details:

accepts a single argument, a list of coins.

$\text{'}$Q$\text{'},\text{'}$D$\text{'},\text{'}$N$\text{'},\text{'}$P$\text{'}$ are the valid values for coins and represent quarter, dime, nickel and

penny, respectively. Each should be valued at their standard US value in whole cents.

$($Assume they will be supplied in upper case.$)$

any other value, for example the the Canadian Quarter $\text{'}$CQ$\text{'},$ should be accepted, but

should not add to the value of the bank

the value of the bank should be returned in whole cents