import scala.math._
import scala.io.Source.stdin

object Main {
  def sumNum(i: Iterator[String]): Vector[BigInt] = {
    def loop(limit: Int, v: Vector[BigInt] = Vector()): Vector[BigInt] =
      if (limit > 0) loop(limit - 1, v :+ (BigInt(i.next) + BigInt(i.next))) else v

    loop(i.next.toInt)
  }

  def main(args: Array[String]): Unit = {
    val input = stdin.getLines
    sumNum(input).foreach(a => if (a.toString.length < 80) println(a) else println("overflow"))
  }
}