#include <iostream>
#include <iostream>
#include <vector>
using namespace std;
string add(string a,string b){

  int numa[1001] = {0},numb[1001] = {0};

  for(int i = a.size()-1 ; i >= 0 ; i-- )numa[a.size()-i-1] = a[i]-'0';
  for(int i = b.size()-1 ; i >= 0 ; i-- )numb[b.size()-i-1] = b[i]-'0';

  vector<int> renum(1001);

  fill(renum.begin(),renum.end(),0);
  int mxsize = max(a.size(),b.size());

  for(int i = 0 ; i < mxsize ; i++ ){
    renum[i+1] = (renum[i] + numa[i] + numb[i])/10;
    renum[i] = (renum[i] + numa[i] + numb[i])%10;
  }

  string srenum = "";
  for(int i = mxsize ; i >= 0 ; i-- ){
    if(i == mxsize && renum[i] == 0)continue;
    srenum += renum[i]+'0';
  }
  return srenum;
}

int main(){
  int n;
  cin >> n;
  while(n--){
    string a,b;
    cin >> a >> b;
    a = add(a,b);
    if(a.size() > 80)cout << "overflow" << endl;
    else cout << a << endl;
  }
  return 0;
}