#include<iostream>
#include<string>
#include<cstring>
using namespace std;

int main(){
	string s1,s2;
	int num;
	cin>>num;
	for(int j=0;j<num;j++){
		cin>>s1;
		cin>>s2;
		int size1=s1.size();
		int size2=s2.size();
		if(size1>80 || size2>80){
			cout<<"overflow"<<endl;
			continue;
		}
		if(size1>size2){
			for(int a=0;a<(size1-size2);a++){
				s2='0'+s2;
			}
		}else if(size1<size2){
			for(int a=0;a<(size2-size1);a++){
				s1='0'+s1;
			}
		}
		string ans="";
		int plus=0;
		for(int i=size1-1;i>=-1;i--){
			if(i==-1){
				if(plus!=0){
					ans=(char)(plus+'0')+ans;
					continue;
				}else{
					continue;
				}
			}
			int alt=(s1[i]-'0')+(s2[i]-'0')+plus;
			if(alt>=10){
				ans=(char)(alt-10+'0')+ans;
				plus=alt/10;
			}else ans=(char)(alt+'0')+ans;
		}
		if(ans.size()>80){
			cout<<overflow<<endl;
		}else{
			cout<<ans<<endl;
		}
	}
	return 0;
}