import std.stdio;
import std.string;
import std.conv;
import std.algorithm;
import std.bigint;

void main(){

    int n;
    readf("%d\n",&n);
    for(int i=0;i<n;i++){
	string s1,s2;
	s1 = chomp(readln());
	s2 = chomp(readln());
	BigInt a = s1;
	BigInt b = s2;
	BigInt c = "10";
	c ^^= 80;
	c -= 1;
	auto res = a + b;
	if(res > c) writeln("overflow");
	else writeln(a + b);
    }
}