$-$Write a C$++$ program that reads data from an input file called "input.txt$"$ and

performs some calculations. The program should then write the results to an

output file called "output.txt$".$

The input file will have the following format:

$-$ The first line will contain an integer, n$,$ which represents the number of values to

be processed.

$-$ The next n lines will each contain a floating$-$point number.

The output file should have the following format:

$-$ The first line should contain the sum of all the values read from the input file.

$-$ The second line should contain the average value of all the values read from the

input file.

Your program should have the following requirements:

$-$ Use file input and output streams to read and write from the files.

$-$ Perform the necessary calculations and output them to the output fil