#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
#define ALL(v) v.begin(),v.end()
string calc(string a,string b){
	reverse(ALL(a));
	reverse(ALL(b));
	while(a.size() < b.size())a += '0';
	while(b.size() < a.size())b += '0';
	int c=0;
	string res;
	for(int i=0;i<a.size();i++){
		c = c+a[i]-'0'+b[i]-'0';
		res += c%10+'0';
		c /= 10;
	}
	if(c)res += c+'0';
	if(res.size() > 80)return "overflow";
	reverse(ALL(res));
	return res;
}
int main(){
	int n;
	string a,b;
	cin>>n;
	while(n--){
		cin>>a>>b;
		cout<<calc(a,b)<<endl;
	}
	return 0;
}