1class Candy:
 2    def __init__(self, mass, uranium):
 3        self.mass = mass
 4        self.uranium = uranium
 5
 6    def get_uranium_quantity(self):
 7        return self.uranium * self.mass
 8
 9    def get_mass(self):
10        return self.mass
11
12
13class Person:
14    def __init__(self, position):
15        self.position = position
16
17    def get_position(self):
18        return self.position
19
20    def set_position(self, position):
21        self.position = position
22
23
24class Kid(Person):
25    def __init__(self, position, initiative):
26        super().__init__(position)
27        self.initiative = initiative
28        self.candies = []
29        self.visited_hosts = set()
30
31    def get_initiative(self):
32        return self.initiative
33
34    def add_candy(self, candy):
35        self.candies.append(candy)
36
37    def is_critical(self):
38        uranium_total = sum(candy.get_uranium_quantity() for candy in self.candies)
39        return uranium_total > 20
40
41    def calculate_distance(self, other_person):
42        x1, y1 = self.position
43        x2, y2 = other_person.position
44        return ((x1 - x2) ** 2 + (y1 - y2) ** 2)
45
46    def get_next_host(self, hosts):
47        unvisited_hosts = [host for host in hosts if host not in self.visited_hosts]
48        if unvisited_hosts:
49            return min(unvisited_hosts, key=lambda host: (self.calculate_distance(host), host.position))
50        return None 
51
52
53class Host(Person):
54    def __init__(self, position, candies):
55        super().__init__(position)
56        self.candies = [Candy(mass, uranium) for mass, uranium in candies]
57
58    def remove_candy(self):
59        if not self.candies:
60            return None
61
62        max_candy = max(self.candies, key=lambda candy: candy.get_mass())
63        self.candies.remove(max_candy)
64        return max_candy
65
66
67class FluxCapacitor:
68    def __init__(self, participants):
69        self.participants = participants
70        self.kids = [participant for participant in participants if isinstance(participant, Kid)]
71        self.hosts = [participant for participant in participants if isinstance(participant, Host)]
72
73    def get_victim(self):
74        while self.kids:
75            for kid in self.kids:
76                host = kid.get_next_host(self.hosts)
77                if host and (candy := host.remove_candy()):
78                    kid.add_candy(candy)
79                    kid.visited_hosts.add(host)
80                    if kid.is_critical():
81                        return {kid}
82            if all(map(lambda kid: len(kid.visited_hosts) == len(self.hosts), self.kids)):
83                return None