import collections
import math
from typing import List, Set, Tuple

############################################################
# Custom Type
# NOTE: You should not modify this.

Position = Tuple[int, int]


############################################################
# Problem 5a

def find_alphabetically_first_word(text: str) -> str:
    return min(text.split())


############################################################
# Problem 5b

def euclidean_distance(loc1: Position, loc2: Position) -> float:
    x1, y1 = loc1
    x2, y2 = loc2
    return math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2)


############################################################
# Problem 5c

def find_non_singleton_words(text: str) -> Set[str]:
  word_count_lol = collections.Counter(text.split())
  return {word for word, count in word_count_lol.items() if count > 1}


############################################################
# Problem 5d

def mutate_sentences(sentence: str) -> List[str]:
    words_in_sentence = sentence.split()
    similar_sentences = []

    if len(words_in_sentence) < 2:
      return similar_sentences

    for i in range(len(words_in_sentence) - 1):
      for j in range(i + 1, len(words_in_sentence)):
        new_sentence = words_in_sentence[:i] + [words_in_sentence[i], words_in_sentence[j]] + words_in_sentence[j + 1:]
        similar_sentences.append(' '.join(new_sentence))

    return similar_sentences
 


if __name__ == "__main__":
    # feel free to modify this for testing purposes
    # print(mutate_sentences('the cat and the mouse'))
   print(find_alphabetically_first_word('hello how are you my apple mango banana'))