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

int reverse(string &s){
	int n = s.size(), n2 = n/2;
	for (int i=0; i<n2; i++)
		swap(s[i], s[n-1-i]);
	return 0;
}

int main(void){
	int n;
	cin>>n;
	for (int i=0; i<n; i++){
		string s1, s2, s3="";
		cin>>s1>>s2;

		reverse(s1);
		reverse(s2);

		while (s1.size()<s2.size()) s1 += '0';
		while (s2.size()<s1.size()) s2 += '0';

		int c=0, stmp;
		for (int i=0; i<s1.size(); i++){
			stmp = s1[i]-'0' + s2[i]-'0' + c;
			c = stmp / 10;
			s3 += stmp%10 +'0';
		}
		if (c!=0) s3 += c + '0';

		reverse(s3);
		if (s3.size()>80)
			cout<<"overflow"<<endl;
		else
			cout<<s3<<endl;

	}
	return 0;
}