>>> from service import service2

>>> ds1 = {'MAIN': [30, 22, 17, 14, 12, 19, 8],
...        'CLEA': [12, 13, 22, 3],
...        'SAFE': [41, 42, 31, 8, 13, 10, 12, 15, 32]}
>>> (tmax1, maxim1) = service2(ds1)
>>> round(maxim1, 2)
22.67
>>> tmax1
'SAFE'

>>> ds2 = {'CLEA': [50], 'SAFE': [9], 'MAIN': [20]}
>>> (tmax2, maxim2) = service2(ds2)
>>> maxim2
50.0
>>> tmax2
'CLEA'

>>> ds3 = {'CLEA': [50, 12, 28, 13, 22, 3, 24], 
...  'MAIN': [30, 22, 17, 12, 14, 21, 12, 19, 15, 8],
...  'SAFE': [41, 42, 31, 8, 10, 13, 10, 12, 15, 32]}
>>> (tmax3, maxim3) = service2(ds3)
>>> round(maxim3, 2)
21.71
>>> tmax3
'CLEA'