//0015
#include <iostream>
#include <string>
#include <algorithm>

using namespace std;
int main(){
	string n1,n2,rn1,rn2,ans="";
	char a='0';
	int b,bb,ro;
	int s1,s2,rs1,rs2,s=0;
	bool up=false;
	int N;
	cin>>N;
	for(int i=0;i<N;i++){
		ans="";
		cin>>n1>>n2;
		n1.length()>=n2.length() ? ro=n1.length() : ro=n2.length();
		reverse(n1.begin(),n1.end());
		rn1=n1;
		reverse(n2.begin(),n2.end());
		rn2=n2;
		//cout<<"_______"<<endl;
		for(int j=0;j<ro+1;j++){
			b=(rn1[j]-'0')+(rn2[j]-'0')+up;
			if(b>=10){
				b=b-10;
				a=b+'0';
				up=true;
			}else{
				a=b+'0';
			}
				ans[s]=a;
				s++;
		}

		if(ans.length()>80){
			cout<<"overflow"<<endl;
		}
		else{
			cout<<ans<<endl;
		}

	}
	return 0;
}