A radar speed gun is a device used in law$-$enforcement to measure the speed of moving vehicles in miles per hour. The measured speeds are supposed to be stored in a file, one number per line, as follows:

$65\mathrm{.}6$

$70\mathrm{.}2$

$54\mathrm{.}9$

Unfortunately, due to an intermittent fault, occasionally multiple numbers are written on a single line as follows:

$73\mathrm{.}265\mathrm{.}669\mathrm{.}8$

Furthermore, occasionally the radar gun outputs a single stray character such as: $67\mathrm{.}9$z$,6$$$4\mathrm{.}9,$ or a$3\mathrm{.}9,$ to illustrate just a few.

Given a file that has radar speed gun readings, write a function averageSpeed$()$ to calculate the average of the numbers in the file. Your code must adhere to the following specifications:

a$.$Prompt the user for the name of the input file to process. When the user enters a nonexistent file name, give the user a second chance. After two wrong entries in a row, quit the program with an appropriate message.

b$.$ Ignore numbers containing stray characters.

c$.$ Ignore any reading for slow vehicles moving at $2$ miles per hour or less.

d$.$ Print the final average to the console.

e$.$ Make use of the functions safeOpen$()$ and safeFloat$()$