def isvowel(letter) :
    if letter == "a" or letter == "e" or letter == "i" or letter == "o" or letter == "u":
        return True
    else:
        return False

print(isvowel("a"))
print(isvowel("b"))
print(isvowel("c"))
print(isvowel("d"))
print(isvowel("e"))



