#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define all(a) (a).begin(),(a).end()
#define pb emplace_back
#define INF (1e9+1)


//#define MAX_V 100001

//MultipleLengthNumber
class MLN{
private:
    string _value;
    
public:
    MLN( string str = "" ):_value(str){}
    
    MLN operator + (MLN obj) {  //verified AOJ0015
        string a = _value, b = obj._value;
        
        if(a.size()<b.size())swap(a,b);         //len(a)>len(b)???
        b = string(a.size()-b.size(),'0')+b;    //b????????????a??¨??????????????????????????????0??§?????????
        
        string ans = string(a.size()+1,'0');    //a?????????+1 ?????????0??§???????????????
        for(int i=(int)a.size()-1;i>=0;i--){    //?¶??????? & ??°????????????
            ans[i+1] += (a[i]-'0') + (b[i]-'0');
            if(ans[i+1]>='0'+10){
                ans[i] += 1;
                ans[i+1] -= 10;
            }
        }
        rep(i,ans.size()){  //??????????????°???0????¶????
            if(ans[i]!='0'||i==ans.size()-1){
                return MLN( ans.substr(i,ans.size()-i) );
            }
        }
        abort();
    }
    
    bool operator > (MLN obj){
        string a = _value, b = obj._value;
        if(a.size() > b.size())return true;
        if(a.size() < b.size())return false;
        
        rep(i,a.size()){
            if(a[i]==b[i])continue;
            if(a[i]>b[i])return true;
            else return false;
        }
        return false;
    }
    
    MLN operator % (MLN obj){
        string a = _value, b = obj._value;
        
        if(MLN(b)>MLN(a))return MLN(a);
        
        string now = a.substr(0,b.size());
        rep(i,a.size()-b.size()+1){
            
        }
        
        return MLN();
    }
    
    
    string value(){
        return _value;
    }
};


int main(){
    int n;
    cin>>n;
    
    rep(i,n){
        string a,b;
        cin>>a>>b;
        string res = (MLN(a)+MLN(b)).value();
        
        if(res.size()>80)cout<<"overflow"<<endl;
        else cout<<res<<endl;
    }
}