>>> from incidencies import primera_incidencia

>>> li = [['X2398','0,0,10,10,0,1,0',1.5], ['X2328','0,1,1,1,0,0,0',1],
... ['X2328','0,1,1,1,0,1,0',2], ['X2328','0,1,1,1,0,1,0',3]]
>>> primera_incidencia(li)
8

>>> li = [['X2398','0,0,10,10,0,1,0',1.5], ['X2328','0,1,1,1,0,0,0',1],
... ['X2328','0,1,1,0,10,1,0',2], ['X2328','0,10,10,10,0,1,0',3]]
>>> primera_incidencia(li)
0

>>> li = [['X8529', '0,1,1,1,0,10,1', 4], ['X6023', '0,10,0,10,10,1,1', 1], ['X3736', '1,0,0,1,10,1,10', 2], ['X5782', '0,0,1,1,1,1,10', 5], ['X7051', '0,0,0,0,0,1,1', 3], ['X6478', '0,0,1,1,0,0,1', 2], ['X8978', '0,1,0,0,1,0,10', 1], ['X3565', '0,1,0,0,0,1,0', 2], ['X2783', '0,0,10,1,1,0,0', 5], ['X4482', '0,1,1,1,1,1,1', 1]]
>>> primera_incidencia(li)
16

>>> li = [['X7759', '1,1,0,0,1,0,0', 2], ['X5625', '10,10,0,0,1,10,0', 3], ['X1853', '1,1,10,1,0,0,1', 5], ['X1785', '1,10,1,10,0,0,10', 1], ['X2955', '0,0,10,1,0,0,10', 3], ['X3314', '0,0,1,1,1,1,0', 5], ['X7967', '0,0,1,1,1,0,0', 5], ['X3737', '0,1,1,10,10,0,0', 3], ['X3934', '0,1,1,1,1,10,0', 4], ['X7462', '0,0,1,0,1,0,0', 3], ['X4291', '10,1,0,0,0,0,1', 4], ['X9370', '10,0,1,0,10,0,1', 2]]
>>> primera_incidencia(li)
20

>>> li = [['X5955', '0,1,0,1,0,0,0', 5], ['X8584', '1,0,0,0,0,0,1', 7], ['X9641', '0,0,1,0,0,0,0', 1], ['X9930', '1,0,1,1,0,1,1', 4], ['X8891', '1,0,1,0,1,0,1', 2], ['X7233', '1,0,0,1,0,0,1', 6], ['X7633', '0,1,1,0,0,0,0', 4], ['X2853', '0,1,1,0,0,1,0', 7], ['X2001', '1,1,1,1,0,1,0', 3]]
>>> primera_incidencia(li)
20

>>> li = [['X8604', '10,10,10,10,10,10,0', 2], ['X3641', '0,10,0,10,1,1,10', 1]]
>>> primera_incidencia(li)
0

>>> li = [['X8119', '10,1,0,10,0,10,10', 5], ['X1846', '10,10,10,10,10,10,10', 1], ['X5456', '10,0,10,1,10,10,10', 10], ['X3514', '10,10,0,1,0,10,0', 1], ['X8560', '1,10,10,10,10,10,10', 8], ['X7960', '10,0,1,10,10,10,10', 7], ['X4138', '1,10,0,0,10,10,10', 6], ['X3752', '10,0,10,10,1,10,10', 2], ['X8378', '10,0,0,10,10,1,1', 6], ['X5206', '10,10,10,1,10,0,10', 5]]
>>> primera_incidencia(li)
8