Strings username$1$ and domain$1$ are read from input. Complete the try block to output "Sending email to $"$ followed by username$1$ and domain$1$ with error checking:

If username$1\text{'}$s length is $<3$ or $>7,$ throw a runtime exception with the message "User name's length must be between $3$ and $7".$

If domain$1$ does not start with $\text{'}$@$\text{'},$ throw a runtime exception with the message "Domain must start with $\text{'}$@$\text{'}".$

Ex: If input is Leroy @lentil, then the output is:

Sending email to Leroy@lentil

Ex: If input is Kjerstin @lentil, then the output is:

Error: User name's length must be between $3$ and $7$

Ex: If input is Leroy peach, then the output is:

Error: Domain must start with $\text{'}$@$\text{'}$

Notes:

username$1.$length$()$ returns the length of string username$1.$

domain$1[0]!=$ ch returns true if the first character of domain$1$ is not character ch$.$ c$++$