1def beginning(word):
 2    remainder = len(word) % 3
 3    addition = remainder and remainder % 2 == 0
 4    end = len(word) // 3 + addition
 5    
 6    return word[:end]
 7
 8def middle(word):
 9    remainder = len(word) % 3
10    addition = remainder and remainder % 2 == 0
11    start = len(word) // 3 + addition
12    end = len(word) - len(word) // 3 - addition
13    
14    return word[start:end]
15
16def end(word):
17    remainder = len(word) % 3
18    addition = remainder and remainder % 2 == 0
19    start = len(word) - len(word) // 3 - addition
20    
21    return word[start:]
22
23def split_sentence(sentence):
24    result = []
25    sentence = sentence.split()
26    
27    for word in sentence:
28        result.append((beginning(word), middle(word), end(word)))
29    
30    return result