>>> from ebill import ebill_calc

--ini

>>> ebill_calc(10.0, 3.0, 200, 1)
(False, 1950)

>>> ebill_calc(7.0, 3.0, 200, 2)
(False, 1500)

>>> ebill_calc(7.0, 3.0, 50, 3)
(False, 450)

>>> ebill_calc(7.0, 3.0, 9, 2)
(False, 90)

>>> ebill_calc(-7.0, 3.0, 9, 2)
(True, 100)

>>> ebill_calc(7.0, -3.0, -10, 2)
(True, 110)

>>> ebill_calc(-7.0, -3.0, -10, 8)
(True, 111)

--fi

>>> ebill_calc(10.0, 6.0, 300, 1)
(False, 2550)

>>> ebill_calc(6.0, 10.0, 300, 2)
(False, 2550)

>>> ebill_calc(10.0, 6.0, 50, 1)
(False, 500)

>>> ebill_calc(6.0, 10.0, 50, 2)
(False, 500)

>>> ebill_calc(7.0, 3.0, 200, 6)
(False, 750)

>>> ebill_calc(6.0, 10.0, 300, 7)
(False, 1275)