interface Activity {
	val startTime: LocalDate
	val endTime: LocalDate
	val quantity: Int
}

data class FullActivity(
	override val startTime: LocalDate,
	override val endTime: LocalDate,
	val directTime: Int,
	val indirectTime: Int,
	override val quantity: Int
) : Activity

data class SpecificActivity(
	val executionTime: LocalDate,
	val duration: Int,
	override val quantity: Int
) : Activity{
	override val startTime: LocalDate get() = executionTime
	override val endTime: LocalDate get() = executionTime.addMinutes(duration)
}