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
  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        self.initiative = initiative
 27        self.basket = []
 28        self.visited_hosts = []
 29        super().__init__(position)
 30
 31    def get_initiative(self):
 32        return self.initiative
 33
 34    def add_candy(self, candy):
 35        self.basket.append(candy)
 36
 37    def is_critical(self):
 38        return sum(candy.get_mass() * candy.get_uranium_quantity() for candy in self.basket) > 20
 39
 40
 41class Host(Person):
 42    def __init__(self, position, candies):
 43        self.candies = []
 44        for candy in candies:
 45            self.candies.append(Candy(candy[0], candy[1]))
 46        self.kids_at_the_moment = []
 47        super().__init__(position)
 48
 49    def remove_candy(self, pick_func):
 50        candy = pick_func(self.candies)
 51        if candy is None:
 52            return None
 53        self.candies.remove(candy)
 54        return candy
 55
 56
 57class FluxCapacitor:
 58    def __init__(self, participants):
 59        self.hosts = []
 60        self.kids = []
 61        for participant in participants:
 62            if isinstance(participant, Host):
 63                self.hosts.append(participant)
 64            if isinstance(participant, Kid):
 65                self.kids.append(participant)
 66
 67    def _getDist(self, host, kid):
 68        x1, y1 = host.get_position()
 69        x2, y2 = kid.get_position()
 70        return ((x2 - x1)**2 + (y2 - y1)**2)**0.5
 71
 72    def _get_closest_unvisited_host(self, kid):
 73        self.hosts = sorted(self.hosts, key=lambda host: (self._getDist(host, kid), host.get_position()))
 74        for host in self.hosts:
 75            if host not in kid.visited_hosts:
 76                kid.visited_hosts.append(host)
 77                kid.position = host.get_position()
 78                return host
 79        return None
 80
 81    def _current_round(self):
 82        dead_kids = set()
 83        for kid in self.kids:
 84            host = self._get_closest_unvisited_host(kid)
 85            host.kids_at_the_moment.append(kid)
 86
 87        for host in self.hosts:
 88            host.kids_at_the_moment = sorted(host.kids_at_the_moment, key=lambda x: x.get_initiative(), reverse=True)
 89            for kid in host.kids_at_the_moment:
 90                if host.candies == []:
 91                    break
 92                candy = host.remove_candy(lambda y: max(y, key=lambda x: x.get_mass(), default=None))
 93                kid.add_candy(candy)
 94                if kid.is_critical():
 95                    dead_kids.add(kid)
 96            host.kids_at_the_moment = []
 97        return dead_kids if dead_kids else None
 98
 99    def get_victim(self):
100        i = 0
101        dead_kids = None
102        while i < len(self.hosts) and dead_kids is None:
103            dead_kids = self._current_round()
104            i += 1
105        return dead_kids