>>> from febles import hi_ha_feble

>>> lc1 = ['101:abc123', '205:123456', '312:password']
>>> hi_ha_feble(lc1)
'password'

>>> lc2 = ['315:superpass3', '209:123456', '101:abcd1234']
>>> hi_ha_feble(lc2)
''
>>> lc3 = ['234:qwerty32', '102:1234', '307:qwerty', '209:joan2024']
>>> hi_ha_feble(lc3)
'1234'

>>> lc4 = ['102:123456', '101:abcdef',  '209:123456', '102:1234']
>>> hi_ha_feble(lc4)
'abcdef'

>>> lc5 = ['234:qwerty32', '102:123456', '235:nomeslletres', '307:qwerty', '209:joan2024']
>>> hi_ha_feble(lc5)
'nomeslletres'