import scala.io.StdIn.{readLine,readInt}

object Main {
  def getDigit(x:Int) = if (x>=10) (x-10,1) else (x,0)


  def getSum(s:String,t:String):String = {
    if(s.length > 80 || t.length > 80) "overflow"
    else {
      val (x,y) = if(s.length>t.length) (s,t) else (t,s)
      val f = (i:Int,j:Int) => if(j<0) x(i).asDigit else x(i).asDigit + y(j).asDigit
      def loop(i:Int,j:Int,sum:List[Int],carry:Int):List[Int] =  {
        if(i<0) { if(carry > 0) carry::sum else sum }
        else {
          val (d,c) = getDigit(f(i,j)+carry)
          loop(i-1, j-1, d::sum, c)
        }
      }
      val r = loop(x.length-1,y.length-1,Nil,0).mkString
      if(r.length > 80) "overflow" else r
    }
  }

  def main(args:Array[String]) = for(i<-1 to readInt) println(getSum(readLine,readLine))
}