old_contents: #!/bin/python3
  
  import math
  import os
  import random
  import re
  import sys
  from collections import Counter
  
  
  def isValid(s):
      return "YES" if containsOnlyOneDifferentCharacterCount(s) else "NO"
  
  
  def containsOnlyOneDifferentCharacterCount(string):
      characterCounts = Counter(string)
      if allOccurencesAreEqual(characterCounts):
          return True
      else:
          # Try to remove one occurence of every character
          for character in characterCounts:
              characterCountWithOneRemovedCharacter = dict.copy(characterCounts)
              characterCountWithOneRemovedCharacter[character] -= 1
              if allOccurencesAreEqual(characterCountWithOneRemovedCharacter):
                  return True
      return False
  
  
  def allOccurencesAreEqual(dict):
      return len(set(dict.values())) == 1
  
  
  if __name__ == '__main__':
      fptr = open(os.environ['OUTPUT_PATH'], 'w')
      s = input()
      result = isValid(s)
      fptr.write(result + '\n')
      fptr.close()
  
new_contents: #!/bin/python3
  
  import math
  import os
  import random
  import re
  import sys
  from collections import Counter
  import copy
  
  
  def isValid(s):
      return "YES" if containsOnlyOneDifferentCharacterCount(s) else "NO"
  
  
  def containsOnlyOneDifferentCharacterCount(string):
      characterCounts = Counter(string)
      if allOccurencesAreEqual(characterCounts):
          return True
      else:
          # Try to remove one occurence of every character
          for character in characterCounts:
              characterCountWithOneRemovedCharacter = characterCounts.copy()
              characterCountWithOneRemovedCharacter[character] -= 1
              characterCountWithOneRemovedCharacter += Counter() # remove zero and negative counts
              if allOccurencesAreEqual(characterCountWithOneRemovedCharacter):
                  return True
      return False
  
  
  def allOccurencesAreEqual(dict):
      return len(set(dict.values())) == 1
  
  
  if __name__ == '__main__':
      fptr = open(os.environ['OUTPUT_PATH'], 'w')
      s = input()
      result = isValid(s)
      fptr.write(result + '\n')
      fptr.close()
  
subject: Handle edge case with zero count