Balance Valid Purchases

You are given an initial balance and a list of financial transactions. Each transaction is represented by a description and an amount. Only transactions whose description is one of the following valid types:

• Purchase at store A
• Refund from store B
• Purchase at store C

should be used to update the balance. The final balance is computed using the formula:

\( balance = initial\_balance + \sum_{t \in valid} amount_t \)

Write a program that reads the input from stdin in the format specified and outputs the final balance to stdout with two decimal places.

inputFormat

The input is given in stdin and has the following format:

1. The first line contains a floating-point number representing the initial balance.
2. The second line contains an integer n representing the number of transactions.
3. The next n lines each contain one transaction in the format: description;amount where description is a string (without the character ';') and amount is a floating-point number.

outputFormat

The output should be printed to stdout and consist of a single line containing the final balance formatted to two decimal places.

100.00
3
Purchase at store A;50.75
Refund from store B;-10.25
Purchase at store C;20.00

160.50