input: Write a function to determine if a given string can be converted to a palindrome by rearranging its characters. If it is possible return True, otherwise return False. The function should consider empty strings as palindromes.
  assert can_form_palindrome("racecar")==True
  assert can_form_palindrome("aabb")==True
  assert can_form_palindrome("abc")==False
  assert can_form_palindrome("")==True
  assert can_form_palindrome("abbac")==True
output: def can_form_palindrome(s):
      from collections import Counter
      count = Counter(s)
      odd_count = sum(1 for v in count.values() if v % 2 != 0)
      return odd_count <= 1