#Prompting user to enter a letter

letter=input("Please enter a letter to check if it is a vowel: ")

#determining if a letter is a vowel or not.
if letter == "a"or"e"or"i"or"o"or"o"or"u"or"A"or"E"or"I"or"O"or"U":
    print("OK")
else:
    print("This letter is not a vowel")