A set of data files named $$exfile$1.$dat$,$exfile$2.$dat$,$ etc. has been created by a series of

experiments. It is not known exactly how many there are, but the files are numbered

sequentially with integers beginning with $1.$ The files all store combinations of numbers

and characters, and are not in the same format. Write a script that will count how many

lines total are in the files. Note that you do not have to process the data in the files in any

way; just count the number of lines.