Hackerrank Maximizing XOR in Scala , several test cases are terminated due to timeout. Possible the number is overflowed.

Maximizing XOR.scala

object Solution {
    def maxXor(l: Int, r: Int): Int = {
       var maxV :Int = 0;
        for(i <- l to r; j <- i to r)
            maxV = maxV.max( i ^ j)
        
         maxV
    }

    def main(args: Array[String]) {
        var _l:Int = Console.readInt
        var _r:Int = Console.readInt
        val res =         maxXor(_l, _r)
        println(res)
    }
}