






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


#define MAX 1000


//99999999999999999999999999999999999999999999999999999999999999999999999999999999

using namespace std;


int main()
{
	int n = 0;
	string in[2];
	char out[MAX] = {NULL};

	cin >> n;

	for (int i = 0; i < n; i++){
		vector<int>v;

		cin >> in[0] >> in[1];

		int len[2];
		len[0] = in[0].size();
		len[1] = in[1].size();

		//けた上がり
		int up = 0;

		for (int i = 0; i < max(len[0] , len[1]) || up == 1; i++){
			
			//足す値
			int push = up;
			up = 0;

			//indexの範囲内
			if(i < len[0]){
				push += in[0][len[0] - i - 1] - '0';
			}
			if (i < len[1]){
				push += in[1][len[1] - i - 1] - '0';
			}
			if (push > 9){
				push -= 10;
				up = 1;
			}

			v.push_back(push);
		}

		if (v.size() > 80){
			cout << "overflow" << endl;
			continue;
		}
		for (int i = v.size() - 1; i >= 0; i--){
			cout << v[i];
		}
		cout << endl;
	}

	return 0;
}