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.mass * self.uranium
  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, new_position):
 21        self.position = new_position
 22
 23
 24class Kid(Person):
 25    THRESHOLD_URANIUM = 20
 26
 27    def __init__(self, position, initiative):
 28        super().__init__(position)
 29        self.initiative = initiative
 30        self.candy_basket = []
 31        self.visited_hosts = set()
 32
 33    def get_initiative(self):
 34        return self.initiative
 35
 36    def add_candy(self, candy):
 37        self.candy_basket.append(candy)
 38
 39    def add_host(self, host):
 40        self.visited_hosts.add(host)
 41
 42    def is_critical(self):
 43        total_uranium = sum(candy.get_uranium_quantity() for candy in self.candy_basket)
 44        return total_uranium > self.THRESHOLD_URANIUM
 45
 46
 47class Host(Person):
 48    def __init__(self, position, candies):
 49        super().__init__(position)
 50        self.candy_basket = [Candy(*candy) for candy in candies]
 51
 52    def remove_candy(self, selection_function):
 53        if self.candy_basket:
 54            selected_candy = selection_function(self.candy_basket)
 55            self.candy_basket.remove(selected_candy)
 56            return selected_candy
 57        else:
 58            return None
 59
 60
 61def find_closest_host(kid, hosts):
 62    closest_host = None
 63    min_distance = float('inf')
 64
 65    for host in hosts:
 66        if host not in kid.visited_hosts and host.candy_basket:
 67            distance = abs(host.get_position()[0] - kid.get_position()[0]) + abs(host.get_position()[1] - kid.get_position()[1])
 68            if distance < min_distance:
 69                min_distance = distance
 70                closest_host = host
 71            elif distance == min_distance:
 72                if host.get_position()[0] < closest_host.get_position()[0]:
 73                    closest_host = host
 74                elif host.get_position()[0] == closest_host.get_position()[0] and host.get_position()[1] < closest_host.get_position()[1]:
 75                    closest_host = host
 76
 77    return closest_host
 78
 79
 80class FluxCapacitor:
 81    
 82    def __init__(self, participants):
 83        self.participants = participants
 84        self.kids = [participant for participant in participants if isinstance(participant, Kid)]
 85        self.hosts = [participant for participant in participants if isinstance(participant, Host)]
 86
 87    @staticmethod
 88    def select_max_mass_candy(candies):
 89        return max(candies, key=lambda candy: candy.get_mass())
 90
 91    def get_victim(self):
 92
 93        victims = set()
 94
 95        while True:
 96            
 97            if all(len(kid.visited_hosts) == len(self.hosts) for kid in self.kids):
 98                return None
 99
100            for kid in self.kids:
101                closest_host = find_closest_host(kid, self.hosts)
102
103                if closest_host:
104                    candy = closest_host.remove_candy(self.select_max_mass_candy)
105                    if candy:
106                        kid.add_candy(candy)
107                        kid.add_host(closest_host)
108                        kid.set_position(closest_host.get_position())
109
110                    if kid.is_critical():
111                        victims.add(kid)
112
113            if not victims:
114                continue
115            else:
116                return victims
117