#include <bits/stdc++.h>
using namespace std;

int main(){
  int N; cin >> N;

  for(int i=0; i<N; i++){
    string S1, S2;
    cin >> S1 >> S2;
    int l1 = S1.length(), l2 = S2.length();

    string S; int carry = 0;
    for(int i=0; i<max(l1, l2)+1; i++){
      if(i < l1 && i < l2){
        int s1 = S1[l1-1-i] - '0', s2 = S2[l2-1-i] - '0';
        char a = (s1+s2+carry) % 10 + '0';
        S.push_back(a);
        if(s1+s2+carry >= 10) carry = 1;
        else carry = 0;
      } else if (i == max(l1, l2)){
        if(carry == 1) S.push_back('1');
      } else if (i >= l1){
        int s2 = S2[l2-1-i] - '0';
        char a = (s2+carry) % 10 + '0';
        S.push_back(a);
        if(s2+carry >= 10) carry = 1;
        else carry = 0;
      } else if(i >= l2){
        int s1 = S1[l1-1-i] - '0';
        char a = (s1+carry) % 10 + '0';
        S.push_back(a);
        if(s1+carry >= 10) carry = 1;
        else carry = 0;
      }
    }
    reverse(S.begin(), S.end());

    if(S.length()>80){
      cout << "overflow" << endl;
    } else {
      cout << S << endl;
    }
  }
}
  
  
