#include<iostream>
using namespace std;
int main(){
  int n;
  cin >>n;
  while(n--){
    string a,b,ans;
    cin >>a>>b;
    int as = a.size(),bs = b.size(),s,c,t=0;
    s = (as<bs)? bs:as;
    for(int i=0; i<s; i++){
      if(i<as && i<bs) c = a[as-i-1]+b[bs-i-1]-'0'*2+t;
      else if(i<as) c = a[as-i-1]-'0'+t;
      else if(i<bs) c = b[bs-i-1]-'0'+t;
      t = c/10;
      ans+=('0'+c%10);
    }
    if(t) ans+='1';
    if(ans.size()>80) cout <<"overflow";
    else for(int i=ans.size()-1; i>=0; i--) cout <<ans[i];
    cout <<endl;
  }
}