#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
  string s,n,final;
  int o,c=0,lim;
  cin>>lim;
  for(int j = 0 ; j < lim ; j++){
    cin>>s>>n;
      reverse(s.begin(),s.end());
    reverse(n.begin(),n.end());
    for(int i = 0; i < s.size() || i<n.size() || c;i++){
      o = (s.size() > i ? s[i]-'0' : 0) +(n.size() > i ? n[i]-'0' : 0) + c;
      
      //   o = (s[i]-'0')+(n[i]-'0')+c;
      c = o / 10;
      o %= 10;
      final.append(1,o+'0');
    }
    reverse(final.begin(),final.end());
    if(n.size()>=80 || s.size()>=80 || final.size()>=80) cout<<"overflow"<<endl;
    else cout<<final<<endl;
    final.clear();
  }
}
  