#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <stdio.h>

using namespace std;

int main()
{
	int i,j,n,f;
	string s1,s2;

	cin>>n;
	
	while(n--){
		cin>>s1>>s2; f=0;
		if(s1.size()<s2.size())swap(s1,s2);

		for(i=0;i<s2.size();i++){s1[i+s1.size()-s2.size()]+=s2[i]-'0';}

		for(i=s1.size()-1;i>0;i--){
			if(s1[i]>'9'){s1[i]-=10; s1[i-1]++;}
		}

		if(s1[0]>'9'){s1[0]-=10;f++;}

		if(s1.size()+f<=80){
			if(f) cout<<"1";
			cout<<s1;
		}
		else cout<<"overflow";

		cout<<endl;
	}
	return 0;
}