#include<iostream>
#include<string>
int a1[1000],a2[1000],c[1000];
using namespace std;
int main(){
 string s1,s2;
 int i,n,l1,l2,l,x=0;
 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++){
     c[i]=a1[i]+a2[i]+x;
     x=c[i]/10;
     c[i]=c[i]%10;
   }
   c[l]=x;
   if (c[l]==1)
    ++l;
   if (l<=80){
     for(i=l-1;i>-1;i--)
       cout<<c[i];
       cout<<endl;
   }
   else {
     cout<<"overflow"<<endl;
     continue;
   }
 }
 return 0;
}