def rovar(word):
    consonants = "bcdfghjklmnpqrstvwxyz"
    vowels = "aeiou"
    rovar = ""
    for letter in word:
        if letter in consonants and letter != "z":
            rovar += letter + vowel(letter) + consonants[consonants.find(letter)+1]
        elif letter == "z":
            rovar += letter + vowel(letter) + letter
        elif letter in vowels:
            rovar += letter
    return rovar

def vowel(letter):
    alphabet = "abcdefghijklmnopqrstuvwxyz"
    vowels = "aeiou"
    diff = 0
    lowest = 20
    closest_vowel = ""
    for vowel in vowels:
        diff = abs(alphabet.find(letter) - alphabet.find(vowel))
        if diff < lowest:
            lowest = diff
            closest_vowel = vowel
    return closest_vowel