#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <string>
#include <cstring>
#include <vector>
#include <map>
#include <utility>
#include <complex>
#include <stack>

using namespace std;

typedef complex<double> P;

int main(){

	int t;
	cin>>t;
	while(t--){
		string s,t;
		cin>>s>>t;
		int len = (int)max(s.size(),t.size());
		reverse(s.begin(),s.end());
		reverse(t.begin(),t.end());
		string ans;

		bool f = false;
		for (int i = 0; i < len; i++)
		{
			char add = 0;
			if(f){
				add++;
				f = false;
			}
			add += (i < (int)s.size()) ? s[i] - '0' : 0;
			add += (i < (int)t.size()) ? t[i] - '0' : 0;
			if(add >= 10){
				add -= 10;
				f = true;
			}
			ans.push_back(add + '0');
		}
		if(f)
			ans.push_back('1');

		reverse(ans.begin(),ans.end());

		if(ans.length() >= 80){
			cout << "overflow" << endl;
		}else {
		cout << ans << endl;
		}
	}
	return 0;
}