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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 read_stdin():
 """ Read text from stdin, and print a helpful message for ttys. """

    if sys.stdin.isatty() and sys.stdout.isatty():
        print('\nReading from stdin until end of file (Ctrl + D)...')

    return sys.stdin.read()