class Sentence:
    def __init__(self,string):
        assert isinstance(string,str)
        self.string = string
            
    def getSentence(self):
        return self.string
    
    def getWords(self):
        return self.string.split()

    def getLength (self):
        return len(self.getSentence()) 

    def getNumWords(self):
        return len(self.getWords())

    def __str__(self):
        return self.getSentence()

    def __repr__(self):
        return 'Sentence(' + repr(self.getSentence()) + ')'

    def __add__(self,other):
        return Sentence(str(self) + ' ' + str(other))

    def __getitem__(self, item):
        return self.getWords()[item]
    
    def __len__(self):
        return self.getNumWords()