object Main extends App {
  val n = readLine.toInt

  for (i <- 0 until n) {
    val maxl = 80
    val a = readLine()
    val b = readLine()

    val res = if (a.length > maxl || b.length > maxl) {
      "overflow"
    } else {
      val c = BigInt(a) + BigInt(b)
      val strc = "%d".format(c)
      if (strc.length > maxl) {
        "overflow"
      } else {
        strc
      }
    }
    println(res)
  }
}
