class Cargo:
    def __init__(self, name, category, size, weight):
        self.name = name
        self.size = size
        self.weight = weight
        self.category = category


class Clothes(Cargo):
    def __init__(self, name, size, weight, fragility):
        super().__init__(name,"clothes", size, weight)
        self.fragility = fragility

class NuclearWaste(Cargo):
    def __init__(self, name, size, weight, exp_date, toxicity):
        super().__init__(name,"nuclear_waste" ,size, weight)
        self.exp_date = exp_date
        self.toxicity = toxicity

class Fruit(Cargo):
    def __init__(self, name ,size, weight, exp_date):
        super().__init__(name,"fruit" ,size, weight)
        self.exp_date = exp_date

class Carparts(Cargo):
    def __init__(self, name ,size, weight):
        super().__init__(name,"car_parts" ,size, weight)

class Forklift:
    def __init__(self, model):
        self.model = model

class Shelf:
    def __init__(self, category):
        self.category = category
        self.items = []

    def add_item(self, item):
        if isinstance(item, Cargo) and item.category == self.category:
            self.items.append(item)
        else:
            print(f"Can't add: {item.name}. Shelf is for: {self.category}")