#include<iostream>
#include<string>
#include<vector>

using namespace std;

void reverse(string *s){
	for(int i=0;i<s->length()/2;i++){
		char tmp=s->at(i);
		s->at(i)=s->at(s->length()-i-1);
		s->at(s->length()-i-1)=tmp;
	}
}

int main(void){
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		string s1,s2;
		cin>>s1;
		cin>>s2;
		if(s1.length()>80||s2.length()>80){
			cout<<"overflow"<<endl;
		}else{
			string s3;
			string tmp;
			if(s1.length()<s2.length()){
				tmp=s1;
				s1=s2;
				s2=tmp;
			}
			int c=0;
			for(int j=0;j<s1.length();j++){
				int tmp;
				if(j<s2.length()){
					tmp=s1[s1.length()-j-1]-'0'+s2[s2.length()-j-1]-'0'+c;
				}else{
					tmp=s1[s1.length()-j-1]-'0'+c;
				}
				c=tmp/10;
				s3.append(1,tmp%10+'0');
			}
			if(c!=0){
				s3.append(1,'1');
			}
			if(s3.length()>80){
				cout<<"overflow"<<endl;
			}else{
				reverse(&s3);
				cout<<s3<<endl;
			}
		}
	}
}