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