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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 crypto_scalarmult_base(n):
 """ Computes and returns the scalar product of a standard group element and an integer ``n``. :param n: bytes :rtype: bytes """

    q = ffi.new("unsigned char[]", crypto_scalarmult_BYTES)

    rc = lib.crypto_scalarmult_base(q, n)
    ensure(rc == 0,
           'Unexpected library error',
           raising=exc.RuntimeError)

    return ffi.buffer(q, crypto_scalarmult_SCALARBYTES)[:]