Scala, how to read more than one integer in one line in and get them in one variable each?

here is my code:

object theater extends App {

    val m = readInt
    val n = readInt
    val a = readInt

    val c1 = m/a + (if(m%a == 0) 0 else 1)
    val c2 = n/a + (if(n%a == 0) 0 else 1)
    print(c1 + c2)
}

But the input format is: 3 integers in the same line. But for 3 integers in one line scala will consider that as a string. How can I read that string and get the 3 values in the 3 separated variables?