// 2012/10/28 Tazoe

#include <iostream>
#include <string>
using namespace std;

int main()
{
	int N;
	cin >> N;

	for(int i=0; i<N; i++){
		string S1, S2;
		cin >> S1;
		cin >> S2;

		if(S1.size()<S2.size()){
			string tmp = S1;
			S1 = S2;
			S2 = tmp;
		}

		if(S1.size()>80){
			cout << "overflow" << endl;
			continue;
		}

		int A[80];
		int C = 0;
		for(int j=0; j<S1.size(); j++){
			int tmp = (int)(S1[S1.size()-1-j]-'0')+C;
			if(j<S2.size()){
				tmp += (int)(S2[S2.size()-1-j]-'0');
			}

			A[j] = tmp%10;
			C = tmp/10;
		}

		if(S1.size()==80&&C==1){
			cout << "overflow" << endl;
		}
		else{
			if(C==1){
				cout << C;
			}
			for(int j=S1.size()-1; j>=0; j--){
				cout << A[j];
			}
			cout << endl;
		}
	}

	return 0;
}