fun main(args: Array<String>) = runBlocking {
    val time = measureTimeMillis {
        val first = async { firstNumber() }
        val second = async { secondNumber() }
        val third = async { thirdNumber() }

        val result = first.await() + second.await() + third.await()
    }

    println(time) //prints 7 seconds
}
suspend fun firstNumber(): Int {
    delay(3_000) // 3 seconds delay
    return 5
}
suspend fun secondNumber(): Int {
    delay(5_000) // 5 seconds delay
    return 8
}
suspend fun thirdNumber(): Int {
    delay(7_000) // 7 seconds delay
    return 10
}
//the above code prints out 7 seconds, which is the time it took the longest running function to return