1class Currency:
 2    def __init__(self, name, rate):
 3        self.name = name
 4        self.rate = rate
 5
 6    def __eq__(self, other):
 7        return isinstance(other, Currency) and self.name == other.name and self.rate == other.rate
 8
 9
10class PoliticalParty:
11    def __init__(self, name, motto, members=None, preferred_currency=None):
12        self.name = name
13        self._motto = motto
14        self.members = members if members else []
15        self.preferred_currency = preferred_currency
16
17    @property
18    def motto(self):
19        return self._motto
20
21    def convert_currency_to_voters(self, amount, currency):
22        voters = int(amount / currency.rate)
23        if self.preferred_currency == currency:
24            voters *= 2
25        return voters
26
27    def __str__(self):
28        return self.name
29
30    def __add__(self, other):
31        if isinstance(other, PoliticalParty):
32            return Coalition(self, other)
33        return NotImplemented
34
35
36class Coalition:
37    def __init__(self, *parties):
38        self.parties = list(parties)
39
40    @property
41    def members(self):
42        return {party.name: party.members for party in self.parties}
43
44    def __add__(self, other):
45        if isinstance(other, PoliticalParty):
46            return Coalition(*self.parties, other)
47        if isinstance(other, Coalition):
48            return Coalition(*self.parties, *other.parties)
49        return NotImplemented
50
51    def __str__(self):
52        return "-".join([party.name for party in self.parties])
53
54
55class Elections:
56    _history = {}
57
58    def __init__(self, year):
59        self.year = year
60        self.result = {}
61        Elections._history[year] = self
62
63    def register_party_or_coalition(self, obj):
64        name = str(obj)
65        if name not in self.result:
66            self.result[name] = 0
67
68    def vote(self, obj):
69        name = str(obj)
70        self.result[name] += 1
71
72    def rig_elections(self, obj, amount, currency):
73        name = str(obj)
74        voters = 0
75
76        if isinstance(obj, PoliticalParty):
77            voters = obj.convert_currency_to_voters(amount, currency)
78        elif isinstance(obj, Coalition):
79            voters = max(
80                party.convert_currency_to_voters(amount, currency)
81                for party in obj.parties
82            )
83
84        self.result[name] += voters
85
86    def get_results(self):
87        return self.result
88
89    @classmethod
90    def get_results_by_year(cls, year):
91        if year in cls._history:
92            return cls._history[year].get_results()
93        return None