import java.math.BigInteger

object Main {
    def main(args:Array[String]) = {
        val sc = new java.util.Scanner(System.in)
        val n = sc.nextInt
        val max = new BigInteger("1"+"0"*80)
        while(sc.hasNext){
	        val a = sc.nextBigInteger
	        val b = sc.nextBigInteger
	        val sum = a.add(b)
	        if(b.compareTo(max) == -1) println(sum)
	        else println("overflow")
	        
    	}
    }
}