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

object Main {

  def add(s:String,t:String):String = {
    val (x,y) = if(s.length>t.length) (s,t) else (t,s)
    val r = new StringBuilder
    var carryOver = 0
    var (i,j) = (x.length-1,y.length-1)

    for(k <- j to 0 by -1) {
      val z = x(i).asDigit+y(k).asDigit+carryOver
      r.insert(0,z%10)
      carryOver = z/10
      i -= 1
    }

    for( k <- i to 0 by -1){
      val z = x(k).asDigit + carryOver
      r.insert(0,z%10)
      carryOver = z/10
    }

    if(carryOver>0) r.insert(0,"1")
    r.result
  }

  def main(args:Array[String]) = {
    val n = readInt
    for(i<-1 to n) {
      val s = readLine
      val t = readLine
      if(s.length > 80 || t.length > 80) println("overflow")
      else {
        val result = add(s,t)
        if(result.length > 80) println("overflow") else println(result)
      }
    }
  }
}