#include<iostream>
#include<string>
using namespace std;
int main(){
 string s1,s2;
 int a1[100],a2[100],i,n,l1,l2,l;
 cin>>n;
 while(n--){
   cin>>s1>>s2;
   l1=s1.size();
   l2=s2.size();
   for(i=l1-1;i>-1;i--)
     a1[i]=int(s1[l1-i-1])-int('0');
   for(i=l2-1;i>-1;i--)
     a2[i]=int(s2[l2-i-1])-int('0');
   if(l1>l2)
     l=l1;
   else
     l=l2;
   for(i=0;i<l;i++){
     a1[i]=(a1[i]+a2[i])%10;
     a1[i+1]+=(a1[i]+a2[i])/10;
   }
   if (a1[l]==1)
    ++l;
   if (l<=80){
     for(i=l-1;i>-1;i--)
       cout<<a1[i];
       cout<<endl;
   }
   else {
     cout<<"overflow"<<endl;
     continue;
   }
 }
 return 0;
}