>>> from repetit import primer_repe

--ini-enunciat

>>> primer_repe([1, 2, 3, 4, 2, 4])
(True, 2)
>>> primer_repe(list('desoxiribonucleic'))
(True, 'e')
>>> primer_repe([1, 2, 3, 4, 5, 6, 7])
(False, None)

--fi-enunciat

>>> primer_repe(list('abracadabra'))
(True, 'a')
>>> primer_repe("visc al bosc i busco vesc i visc del vesc que busco al bosc".split())
(True, 'visc')
>>> primer_repe("una cabra caga pebre".split())
(False, None)