#include<cstdio>
#include<algorithm>
#include<vector>
#include<string>
#include<iostream>
#include<queue>
#include<map>
#include<set>
#include<complex>
#include<stack>
 
using namespace std;
 
int main(){
     
    int n;
    cin>>n;
     
	while(n-- > 0){
        vector<int> ans;
        vector<int> a;
        vector<int> b;
         
        string c,d;
        cin>>c>>d;
         
		for(int i = 0; i < (int)c.size(); ++i){
            a.push_back(c[c.size()-1-i]-'0');
        }
		for(int i = 0; i < (int)d.size(); ++i){
            b.push_back(d[d.size()-1-i]-'0');
        }
         
         
        int kuri = 0;
        while(!a.empty() || !b.empty() || kuri!=0){
            int sum = kuri;
            kuri = 0;
             
            if(!a.empty()){
                sum += a[0];
                a.erase(a.begin());
            }
             
            if(!b.empty()){
                sum += b[0];
                b.erase(b.begin());
            }
             
            ans.push_back(sum%10);
            kuri += sum/10;
        }
         
        if(ans.size()>80)puts("overflow");
        else{
			for(int i = 0; i < (int)ans.size(); ++i){
                printf("%d",ans[ans.size()-1-i]);
            }puts("");
        }
    }
     
}

/*
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	int n;
	cin >> n;
	
	while(n-- > 0){
	
	string str1;
	cin >> str1;
	
	string str2;
	cin >> str2;
	
	reverse(str1.begin(), str1.end());
	reverse(str2.begin(), str2.end());
	
	int check;
	if(str1.size() > str2.size()){
		check = 1;
	}
	else if(str1.size() == str2.size()){
		check = 2;
	}
	else {
		check = 3;
	}
	
	int ans[100];
	bool next = false;
	int short_ = min(str1.size(), str2.size());
	int long_ = max(str1.size(), str2.size());	
	if(long_ >= 80){
		cout << "overflow" << endl;
		continue;
	}

	for(int i = 0; i < short_; ++i){
		int num = 0;
		num += (str1[i] - '0') + (str2[i] - '0');
		if(next){
			num++;
		}
		ans[i] = num;
		next = false;	
		if(num >= 10){
			num -= 10;
			ans[i] -= 10;
			next = true;
		}
	}
	
	if(check == 1){
		for(size_t i = str2.size(); i < str1.size(); ++i){
			int num = str1[i] - '0';
			if(next){
				num++;
			}
			ans[i] = num;
			next = false;	
			if(num >= 10){
				num -= 10;
				ans[i] -= 10;
				next = true;
			}
		}
		if(next){
			ans[str1.size()] = 1;
			long_ ++;
		}
	}	
	
	if(check == 3){
		for(size_t i = str1.size(); i < str2.size(); ++i){
			int num = str2[i] - '0';
			if(next){
				num++;
			}
			ans[i] = num;
			next = false;	
			if(num >= 10){
				num -= 10;
				ans[i] -= 10;
				next = true;
			}
		}
		if(next){
			ans[str2.size()] = 1;
			long_ ++;
		}
	}
	
	if(long_ >= 80){
		cout << "overflow" << endl;
		continue;
	}

	for(int i = long_ - 1; i >= 0; --i){
		cout << ans[i];
	}	
	cout << endl;
	}
		
	return 0;
}
*