Read a $3-$character string from input into variable userString. Declare a Boolean variable isValid and assign isValid with true if userString does not contain any alphabetic characters. Otherwise, assign isValid with false.

Ex: If the input is $87\%,$ then isValid is assigned with true, so the output is:

String is valid

Ex: If the input is $6$v$1,$ then isValid is assigned with false, so the output is:

String is not valid

Note: Use userString $=$ scnr$.$nextLine$()$ to read the entire line from input into userString.