#include<iostream>
#include<stack>
using namespace std;

int main(void){
  string x,y;
  int tmp, c;
  int N;
  int cnt;
  cin >> N;

  for(int i = 0; i < N; i++){
    stack<int> a, b, ans;
    cnt = 0;

    cin >> x;
    cin >> y;

    for(int j = 0; j < x.length(); j++){
      a.push(x[j] - '0');
    }
    for(int j = 0; j < y.length(); j++){
      b.push(y[j] - '0');
    }

    c = 0;

    while(a.empty() != true || b.empty() != true){
      tmp = 0;
      
      if(a.empty() != true){
	tmp += a.top();
	a.pop();
      }
      if(b.empty() != true){
	tmp += b.top();
	b.pop();
      }
      tmp += c;

      ans.push(tmp % 10);
      cnt++;

      if(tmp >= 10)
	c = tmp / 10;
      else
	c = 0;
    }

    if(c != 0){
      ans.push(c);
      cnt++;
    }

    if(cnt > 80)
      cout << "overflow" << endl;
    else{
      while(ans.empty() != true){
	cout << ans.top();
	ans.pop();
      }
      cout << endl;
    }
  }
  return 0;
}