#include <iostream>
#include <cstdio>
#include <memory>
#include <string>
#include <algorithm>

using namespace std;

int main(void){
    int n;
    string a,b,ans;
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        ans="";
        cin>>a>>b;
        if(a.size()>80||b.size()>80){
            cout<<"overflow"<<endl;
            continue;
        }
        reverse(a.begin(),a.end());
        reverse(b.begin(),b.end());
        int size=(a.size()>b.size())?a.size():b.size();
        bool af=false,bf=false,uf=false;
        for(int j=0;j<size;j++){
            int pr=0;
            if(a.size()<j+1)af=true;
            if(b.size()<j+1)bf=true;
            if(!af){
                pr+=a[j];
                pr-=48;
            }
            if(!bf){
                pr+=b[j];
                pr-=48;
            }
            if(uf)pr++;
            if(pr>9){
                pr-=10;
                uf=true;
            }else uf=false;
            pr+=48;
            ans=(char)pr+ans;
        }
        if(uf)ans='1'+ans;
        if(ans.size()>80)cout<<"overflow"<<endl;
        else cout<<ans<<endl;
    }
}

