#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
	string a,b,c;
	int n;
	cin>>n;
	for(int fjal=0;fjal<n;fjal++){
	cin>>a>>b;
	c.clear();
	if(a.size()<b.size())swap(a,b);
	int as=a.size();
	while(as!=b.size())b="0"+b;
	//cout<<a<<" "<<b;
	bool kuri=false;
	for(int i=as-1;i>=0;i--){
		int _a=a[i]-'0',_b=b[i]-'0',ans=_a+_b;
		if(kuri)ans++;
		if(ans>=10){
			kuri=true;
			ans-=10;
		}
		else {kuri=false;}
		//cout<<ans<<" "<<i;
		c.push_back(ans+'0');
	}
		if(kuri)c.push_back('1');
		string ans;
		if(c.size()<80){for(int i=c.size()-1;i>=0;i--)ans.push_back(c[i]);
		cout<<ans<<endl;
		}
		else cout<<"overflow"<<endl;
	}
	return 0;
}