def letter_dict(text):
    """
    letter count dictionary
    """
    text = text.lower()
    replacements = {'á': 'a', 'é': 'e', 'í': 'i', 'ó': 'o', 'ú': 'u', 'ü': 'u'}
    for i, j in replacements.items():
        text = text.replace(i, j)
    letterlist = list(filter(None, map(lambda c: c if c.isalpha() else '',
        text)))
    letterdict = dict()
    for letter in letterlist:
        letterdict[letter] = letterdict.get(letter, 0) + 1
    return letterdict
