input: from collections import Counter
  
  def minimal_anagram_length(s: str) -> int:
      """
      Given a string s that is a concatenation of anagrams of a string t, determine the shortest possible length of t.
  
      An anagram is a word or phrase formed by rearranging the letters. For instance, "aab", "aba", and "baa" are all anagrams of "aab".
  
      Examples:
      >>> s = "abba"
      2
      >>> s = "cdef"
      4
  
      Constraints:
      1 <= s.length <= 10^5
      s contains only lowercase English letters.
      """
output:     
      counter = Counter(s)
      return len(counter)
  