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

int main(){
  int n;
  string up,un;
  cin >> n;
  while(n--){
    cin >> up >> un;
    if(up.size() > 80 || un.size() > 80){
    exit:
      cout << "overflow\n";
      continue;
    } 
    if(up.size() < un.size()) swap(up,un);
    for(int i=up.size()-1,j=un.size()-1;i>=0;i--,j--){
      if(j >= 0) up[i] += un[j]-'0';
      if(up[i] > '9'){
	up[i] -= 10;
	if(i == 0) up = "1" + up;
	else up[i-1]++;
      }
    }
    if(up.size() > 80) goto exit;
    cout << up << endl;
  }
}