Write a program to concatenate two strings $($first name and last name$)$ entered by the user

$($from keyboard$).$ The program will print concatenated string as well as length of the

concatenated string as well as the concatenated length

a$.$ Using cin and cout, prompt the user for and read in first name.

b$.$ Using cin and cout, prompt the user for and read in last name.

c$.$ Concatenate two strings using $+$ operator.

d$.$ Determine the length of the concatenated string using length $()$ function