input: Write a python function that takes a string as input and checks if there is any substring of length 2 which also appears in the string reversed. The function should return true if it finds such a substring and false if it doesn't.
  
  Examples:
  >>> s = "leetcode"
  true
  >>> s = "abcba"
  true
  >>> s = "abcd"
  false
  
  Constraints:
  1 <= s.length <= 100
  s consists only of lowercase English letters.
output: def has_reversed_substring(s):
      for i in range(len(s) - 1):
          if s[i:i+2] == s[i:i+2][::-1]:
              return True
      return False