#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

string add(string a, string b) {
  while(a.size() < b.size()) a.insert(0, "0");
  while(b.size() < a.size()) b.insert(0, "0");
  int n = a.size();
  string res(n, ' ');
  for(int i = n-1, d = 0; i >= 0; --i) {
    int p = a[i]-'0';
    int q = b[i]-'0';
    int r = p+q+d;
    d = r/10;
    res[i] = r%10 + '0';
    if(i == 0 && d != 0) res.insert(0, string(1,d+'0'));
  }
  return res;
}

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