Read a $2-$character string from input into variable userString. Declare a Boolean variable isValid and assign isValid with true if userString does not contain any lowercase letters. Otherwise, assign isValid with false.

Ex: If the input is $0$J$,$ then isValid is assigned with true, so the output is:

Valid string

Ex: If the input is dj$,$ then isValid is assigned with false, so the output is:

Invalid string