class Field:
    def __init__(self, horizontal_index, vertical_index, state):
        self.__horizontal_index = horizontal_index
        self.__vertical_index = vertical_index
        self.__state = state

    @property
    def state(self):
        return self.__state

    @property
    def horizontal_index(self):
        return self.__horizontal_index

    @property
    def vertical_index(self):
        return self.__vertical_index

    @state.setter
    def state(self, state):
        if state == "toPlow" or state == "toWater" or state == "toSeed" or \
                state == "toFertilize" or state == "toCut" or state == "TOOLS_FIELD" or state == "FUEL_FIELD":
            self.__state = state