#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
int main() {
	int N;
	cin>>N;
	for(int i=0;i<N;i++) {
		string A,B,C;
		cin>>A>>B;
		reverse(A.begin(),A.end());
		reverse(B.begin(),B.end());
		for(int i=0;i<A.size()||i<B.size();i++) {
			int n=0;
			if(i<A.size())n+=(A[i]-'0');
			if(i<B.size())n+=(B[i]-'0');
			C.push_back(n);
		}
		for(int i=0;i<C.size();i++) {
			if(i!=C.size()-1)C[i+1]+=C[i]/10,C[i]%=10;
		}
		reverse(C.begin(),C.end());
		if(C.size()>80) {
			cout<<"overflow"<<endl;
		}else {
			for(int i=0;i<C.size();i++) {
				if(C[i]>=10) {
					cout<<(char)(C[i]/10+'0');
					cout<<(char)(C[i]%10+'0');
				}else cout<<(char)(C[i]+'0');
			}
			cout<<endl;
		}
	}
}