```
//a: "apple" , b : "pleqwe" . ==> result: 3 (length of "qwe")
def findLUSlength(a: String, b: String): Int = {
if (a.equals(b)) return -1
val intersect = a.intersect(b)
val aBefore = a.substring(0, a.indexOf(intersect)).length
val aBehind = a.substring(a.indexOf(intersect), a.length).length - intersect.length
val bBefore = b.substring(0, b.indexOf(intersect)).length
val bBehind = b.substring(b.indexOf(intersect), b.length).length - intersect.length
Math.max(Math.max(aBefore, aBehind), Math.max(bBefore, bBehind))
}
```