class Solution:
  def findLength(self, text, k):
      max_length = float('-inf')
      freq = {}
      j = 0
      
      for i in range(len(text)):
        freq[text[i]] = freq.get(text[i], 0)
        freq[text[i]] += 1 
        if len(freq) <= k:
          max_length = max(max_length, i - j + 1)
        else:
          while len(freq) > k:
            freq[text[j]] -= 1 
            if freq[text[j]] == 0:
              del freq[text[j]]
            j += 1
          
      return max_length