1-Old.kt

data class Sprint(val todoTasks: Int, val doneTasks: Int)

fun main() {
    val sprint1 = Sprint(51, 20)
    val sprint2 = Sprint(30, 40)
    
    val totalTodoTasks = sprint1.todoTasks + sprint2.todoTasks	// 51 + 30
    val totalDoneTasks = sprint1.doneTasks + sprint2.doneTasks	// 20 + 40
    
    val newSprint = Sprint(totalTodoTasks, totalDoneTasks)
}

2-New.kt

data class Sprint(val todoTasks: Int, val doneTasks: Int) {
    operator fun plus(other: Sprint): Sprint {
        return Sprint(todoTasks + other.todoTasks, doneTasks + other.doneTasks)
    }
}

fun main() {
    val sprint1 = Sprint(51, 20)
    val sprint2 = Sprint(30, 40)

    val newSprint = sprint1 + sprint2
}