I am learning Kotlin from this [1] and at 35:45 he is running this code: [enter image description here][2] I ve tried to run exactly the same code: fun main() { val x = readLine()?:"1" val y = readLine()?:"1" val z = x.toInt() + y.toInt() print(z) } But i get this error: Exception in thread… Read More Elvis operator doesn't work in Kotlin while the synthax seems correct