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