#include <iostream>
using namespace std;
int main(){
	string s1, s2;
	int n;
	cin>>n;
	while(n--){
		string m1, m2, m;
		int k=0;
		cin>>s1>>s2;
		if(s1.length()>80 || s2.length()>80){
			cout<<"overflow"<<endl;
		}
		else{
			if(s1.length()<s2.length()){
				string memo=s1;
				s1=s2;
				s2=memo;
			}
			int c1=s1.length(), c2=s2.length();
			for(int i=s2.length()-1; i>=0; i--){
				k+=s1[i+c1-c2]-'0'+s2[i]-'0';
				m=to_string(k%10)+m;
				k=k/10;
			}
			for(int i=c1-c2-1; i>=0; i--){
				k+=s1[i]-'0';
				m=to_string(k%10)+m;
				k=k/10;
			}
			if(k==1)
				m=to_string(k)+m;
			if(m.length()>80)
				cout<<"overflow"<<endl;
			else
				cout<<m<<endl;
		}
	}
	return 0;
}

