Write a program to print all the unique characters in a given sentence.
The sentence should have only alphabets .
If the sentence is not valid display the message "Invalid Sentence".
If unique characters are not found print "No unique characters".
If unique characters are found print those characters as shown in sample output.
Sample Input 1:
Enter the sentence:
java is an object oriented programming language
Sample Output 1:
Unique characters:
v
s
b
c
d
p
l
u
Sample Input 2:
Welcome to 12house
Sample Output 2:
Invalid Sentence