a. The Last National Bank has two branches, each of which uses a sequential file containing a summary of customers’ checking accounts in the following form:

account_number(Integer), customer_name(String), balance(Float)

The files, which are called "account1" and "account2", are ordered by account number in increasing order. (Assume that no two account numbers are the same.) Due to financial reverses, one of the branches must be closed, and the two files need to be merged into a single one called "account3". Write a program to perform this operation.

b. Suppose that some of the records in "account1" and "account2" are the same. Modify the appropriate module of the program so that only one of the duplicate account records is written to the file "account3".