#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
  int n;
  cin >>n;
  while(n--){
    string a,b,c;
    cin >>a>>b;
    int s_a=a.size(),s_b=b.size();
    int s_max = max(s_a,s_b),s_min = min(s_a,s_b);
    int x=0, y=0;
    for(int i=0; i<s_max; i++){
      if(i<s_min) x = a[s_a-i-1]+b[s_b-i-1]-'0'*2+y;
      else if(i<s_a) x = a[s_a-i-1]-'0'+y;
      else if(i<s_b) x = b[s_b-i-1]-'0'+y;
      y = x/10;
      c+=(char)('0'+x%10);
    }
    if(y>0) c+='1';
    if(c.size()>80) cout <<"overflow";
    else for(int i=c.size()-1; i>=0; i--) cout <<c[i];
    cout <<endl;
  }
  return 0;
}