Determine the number of different vowels that appear in a given sentence.
A single line of text.
A single line describing the number of different vowels that appear in the text. No distinction must made between uppercase and lowercase letters in counting the number of vowels.
And now for something completely different.
The sentence contains 4 different vowels.
Spam! Spam! Spam! Spam! Spam! Spam!
The sentence only contains 1 different vowel.
Nbdy xpcts th Spnsh nqstn!
The sentence contains no vowels.