#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
  int n;
  cin >>n;
  cin.ignore();
  while(n--){
    string one;
    string two;
    string ans[200];
    getline(cin,one);
    getline(cin,two);
    int os = one.size()-1, ts = two.size()-1;
    int ls = max(os,ts), ss = min(os,ts);
    int as = 0,x,t = 0;
    for(int i=0; i<=ls; i++){
      if(i<=os && i<=ts){x = one[os-i]+two[ts-i]-'0'*2+t;}
      else if(i<=os){x = one[os-i]-'0'+t;}
      else if(i<=ts){x = two[ts-i]-'0'+t;}
      t = x/10;
      x = x%10;
      ans[i] = x+'0';
      as++;
    }
    if(t>0){ans[as+1] = t+'0';as++;}
    if(as>=80){cout <<"overflow"<<endl;}
    else{
      for(int i=as; i>=0; i--){
	cout <<ans[i];
      }
      cout <<endl;
    }
  }
  return 0;
}