#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <string>
#include <sstream>
#include <iomanip>
 
#define INPUT_FROM_FILE (0)
#if INPUT_FROM_FILE
#include <fstream>
#endif

void str_to_vec(std::string str, std::vector<char> &v){
	v.clear();
	for(int i = str.size() - 1; i >= 0; i--){
		v.push_back(str[i] - 48);
	}
	return;
}

std::vector<char> sum(std::vector<char> &v0, std::vector<char> &v1){
	std::vector<char> ret;
	char carry = 0;

	if(v0.size() < v1.size()){
		std::swap(v0, v1);
	}
	for(unsigned int i = 0; i < v1.size() - v0.size(); i++){
		v1.push_back(0);
	}

	ret.resize(v1.size(), 0);

	for(unsigned int i = 0; i < ret.size(); i++){
		char tmp = v0[i] + v1[i] + carry;
		if(tmp >= 10){
			carry = 1;
			tmp -= 10;
		}
		else{
			carry = 0;
		}
		ret[i] = tmp;
	}
	if(carry == 1){
		ret.push_back(1);
	}

	return ret;
}

int main(int argc, char **argv){
	int n = 0;
	std::string buf;

#if INPUT_FROM_FILE
	std::ifstream ifs("test.txt");
#endif



#if INPUT_FROM_FILE
	std::getline(ifs, buf);
#else
	std::getline(std::cin, buf);
#endif
	n = std::stoi(buf);

	for(int i = 0; i < n; i++){
		std::vector<char> num0;
		std::vector<char> num1;
#if INPUT_FROM_FILE
		std::getline(ifs, buf);
#else
		std::getline(std::cin, buf);
#endif
		str_to_vec(buf, num0);
#if INPUT_FROM_FILE
		std::getline(ifs, buf);
#else
		std::getline(std::cin, buf);
#endif
		str_to_vec(buf, num1);

		if(num0.size() > 80 || num1.size() > 80){
			std::cout << "overflow" << std::endl;
		}
		else{
			std::vector<char> s = sum(num0, num1);

			if(s.size() > 80){
				std::cout << "overflow" << std::endl;
			}
			else{
				for(int i = s.size() - 1; i >= 0; i--){
					std::cout << (int)s[i];
				}
				std::cout << std::endl;
			}
		}
	}
	return 0;
}
