basic42

object basic42 {
  def f(n:Int):Int = {
    if(n==1){
      1
    }else if(n==2){
      2
    }else{
      f(n-1)+f(n-2)
    }
  }
  def main(args: Array[String]): Unit = {
    val rst = f(5)
    println(rst)
  }
}
```
```