input: Write a function to find the largest palindrome in a given phrase.
  assert find_largest_palindrome("Quick brown fox") == "oo"
  assert find_largest_palindrome("A man a plan a canal Panama") == "anana"
  assert find_largest_palindrome("No lemon no melon") == "noon"
output: def find_largest_palindrome(phrase):
      def is_palindrome(s):
          return s == s[::-1]
      
      words = phrase.split()
      largest_palindrome = ""
      
      for word in words:
          for start in range(len(word)):
              for end in range(start + 1, len(word) + 1):
                  substring = word[start:end]
                  if is_palindrome(substring) and len(substring) > len(largest_palindrome):
                      largest_palindrome = substring
      
      return largest_palindrome