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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def cwd(self):
 """ Return a UNIX FS type string of the current working 'directory'. """

            l_cwd                       = self.l_cwd[:]
            str_cwd                     = '/'.join(l_cwd)
            if len(str_cwd)>1: str_cwd  = str_cwd[1:]
            return str_cwd