#include <iostream>
#include <string>
#include <algorithm>
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
using namespace std;

int main(void){
	int N;
	cin >> N;
	for(int n=0;n<N;n++){
		string s1,s2,s3;
		cin >> s1 >> s2;
		reverse(s1.begin(),s1.end());
		reverse(s2.begin(),s2.end());
		bool up=false;
		for(int i=0;i<s1.size()||i<s2.size();i++){
			if(i<s1.size()&&i<s2.size()){
				int sum=0;
				if(up)sum++;
				sum+=(s1[i]+s2[i]-'0'-'0');
				s3+=(sum%10)+'0';
				if(sum>=10)
					up=true;
				else
					up=false;
			}else if(i<s1.size()){
				int sum=0;
				if(up)sum++;
				sum+=(s1[i]-'0');
				s3+=(sum%10)+'0';
				if(sum>=10)
					up=true;
				else
					up=false;
			}else if(i<s2.size()){
				int sum=0;
				if(up)sum++;
				sum+=(s2[i]-'0');
				s3+=(sum%10)+'0';
				if(sum>=10)
					up=true;
				else
					up=false;
			}
		}
		if(up)
			s3+='1';
		if(s3.size()>80)
			cout << "overflow" << endl;
		else{
			reverse(s3.begin(),s3.end());
			cout << s3 << endl;
		}
	}
	return 0;
}