#include<iostream>
#include<vector>
#include<algorithm>
#include<string>

void swap(std::string& str1, std::string& str2)
{
	std::string temp;

	temp = str1;

	str1 = str2;

	str2=temp;
}

int main()
{
	int n=0;

	std::cin >> n;

	for(int i=0; i<n; ++i)
	{
		std::vector<int> a, b;

		std::string stra, strb;

		std::cin >> stra >> strb;

		if(stra.length()<strb.length())
		{
			swap(stra,strb);
		}

		for(size_t i=0; i<stra.length(); ++i)
		{
			a.push_back(stra[stra.length()-1-i]-48);
		}

		for(size_t i=0; i<strb.length(); ++i)
		{
			b.push_back(strb[strb.length()-1-i]-48);
		}

		for(size_t i=0; i<b.size(); ++i)
		{
			a[i] += b[i];
		}

		for(size_t i=0; i<a.size()-1; ++i)
		{
			if(a[i]>=10)
			{
				++a[i+1];

				a[i] %= 10;
			}
		}

		if(a[a.size()-1]>=10)
		{
			a[a.size()-1] %= 10;

			a.push_back(1);
		}
		
		if(a.size()>80)
		{
			std::cout << "overflow";
		}
		else
		{
			for(size_t i=0; i<a.size(); ++i)
			{
				std::cout << a[a.size()-1-i];
			}	
		}

		std::cout << '\n';
	}
}