# https://www.codewars.com/kata/54bf1c2cd5b56cc47f0007a1
#
# ### Count the number of Duplicates
#
# Write a function that will return the count of **distinct case-insensitive**
# alphabetic characters and numeric digits that occur more than
# once in the input string.
# The input string can be assumed to contain only alphabets (both uppercase and
# lowercase) and numeric digits.
#
#
# ### Example
# "abcde" -> 0             `# no characters repeats more than once`
# "aabbcde" -> 2           `# 'a' and 'b'`
# "aabBcde" -> 2           ``# 'a' occurs twice and 'b' twice (`b` and `B`)``
# "indivisibility" -> 1    `# 'i' occurs six times`
# "Indivisibilities" -> 2  `# 'i' occurs seven times and 's' occurs twice`
# "aA11" -> 2              `# 'a' and '1'`
# "ABBA" -> 2              `# 'A' and 'B' each occur twice`


def duplicate_count(text):
    t = text.lower()
    l = list(t)

    for item in set(t):
        l.remove(item)
    return len(set(l))
