#include<iostream>
#include<string>
using namespace std;
int main(){
  int n;
  cin >>n;
  while(n--){
    string a,b,ans;
    cin >>a>>b;
    int as = a.size(), bs = b.size(), ms = (as>bs)? as:bs,t=0;
    for(int i=0; i<ms; i++){
      if(i<as && i<bs){t = a[as-i-1]+b[bs-i-1]+t/10-2*'0';}
      else if(i<as){t = a[as-i-1]+t/10-'0';}
      else if(i<bs){t = b[bs-i-1]+t/10-'0';}
      ans+=(char)(t%10)+'0';
    }
    if(t/10){ans+='1';}
    if(ans.size()>80){cout <<"overflow"<<endl;}
    else{for(int i=0; i<ans.size(); i++){cout <<ans[ans.size()-i-1];}cout <<endl;}
  }
  return 0;
}