1class Basket:
  2    def __init__(self):
  3        self.candies = []
  4        self.candy_givers = []
  5    
  6    def add_candy(self, candy):
  7        self.candies.append(candy)
  8
  9    def add_giver(self, giver):
 10        self.candy_givers.append(giver)
 11
 12    def remove_candy(self, candy):
 13        self.candies.remove(candy)
 14
 15    def get_candies(self):
 16        return self.candies
 17    
 18    def fill(self, candies):
 19        self.candies = candies
 20
 21
 22class Candy:
 23    def __init__(self, mass, uranium):
 24        self.mass = mass
 25        self.uranium = uranium
 26    
 27    def get_uranium_quantity(self):
 28        return self.mass * self.uranium
 29    
 30    def get_mass(self):
 31        return self.mass
 32
 33
 34class Person:
 35    def __init__(self, position):
 36        self.position = position
 37        self.basket = Basket()
 38
 39    def get_position(self):
 40        return self.position
 41    
 42    def set_position(self, new_position):
 43        self.position = new_position
 44    
 45    def get_distance(self, other_person):
 46        return (self.position[0] - other_person.position[0]) ** 2 + (self.position[1] - other_person.position[1]) ** 2
 47
 48
 49class Kid(Person):
 50    MIN_URANIUM_TO_UNLOCK_POWER = 20
 51
 52    def __init__(self, position, initiative):
 53        super().__init__(position)
 54        self.initiative = initiative
 55
 56    def get_initiative(self):
 57        return self.initiative
 58    
 59    def add_candy(self, candy):
 60        self.basket.add_candy(candy)
 61    
 62    def is_critical(self):
 63        return sum(candy.get_uranium_quantity() for candy in self.basket.get_candies()) > self.MIN_URANIUM_TO_UNLOCK_POWER
 64    
 65    def visit_closest_host(self, hosts):
 66        min_distance = None
 67        closest_host = None
 68        
 69        for host in hosts:
 70            distance = self.get_distance(host)
 71            host_position = host.get_position()
 72            closest_position = closest_host.get_position() if closest_host else None
 73
 74            if host in self.basket.candy_givers:
 75                continue
 76
 77            if (
 78                min_distance is None or
 79                (distance, host_position[0], host_position[1]) < (min_distance, closest_position[0], closest_position[1])
 80            ):
 81                min_distance = distance
 82                closest_host = host
 83
 84        return closest_host
 85    
 86
 87class Host(Person):
 88    def __init__(self, position, candies):
 89        super().__init__(position)
 90        self.basket.fill([Candy(mass, uranium) for mass, uranium in candies])
 91
 92    def remove_candy(self, candy_picker):
 93        if not len(self.basket.get_candies()):
 94            return
 95        
 96        picked_candy = candy_picker(self.basket.get_candies())
 97        self.basket.remove_candy(picked_candy)
 98
 99        return picked_candy
100    
101    def give_candy(self, kids, candy_picker):
102        kids = sorted(kids, key=lambda kid: kid.initiative, reverse=True)
103        for kid in kids:
104            picked_candy = self.remove_candy(candy_picker)
105            kid.basket.add_giver(self)
106            if picked_candy:
107                kid.add_candy(picked_candy)
108
109
110class FluxCapacitor:
111    def __init__(self, participants):
112        self.participants = participants
113
114    def get_victim(self):
115        kids = [participant for participant in self.participants if type(participant) is Kid]
116        hosts = [participant for participant in self.participants if type(participant) is Host]
117        kids_who_glow_in_the_dark = set()
118
119        while not len(kids_who_glow_in_the_dark):
120            visitings = []
121
122            for kid in kids:
123                closest_host = kid.visit_closest_host(hosts)
124                if closest_host:
125                    visitings.append((kid, closest_host))
126                    kid.set_position(closest_host.get_position())
127
128            if not len(visitings):
129                return
130            
131            for host in hosts:
132                host.give_candy(
133                    (kid_host_pair[0] for kid_host_pair in visitings if kid_host_pair[1] == host),
134                    self.get_biggest_mass_candy
135                )
136
137            kids_who_glow_in_the_dark = {kid for kid in kids if kid.is_critical()}
138
139        return kids_who_glow_in_the_dark
140
141    @staticmethod
142    def get_biggest_mass_candy(candies):
143        return max(candies, key=lambda candy: candy.get_mass())