/*
	0015:National Budget
*/
#include	<iostream>
#include	<string>
#include	<iterator>

using namespace std;

int main(void) {
	int n;
	
	cin >> n;
	for(int i = 0; i < n; i++) {
		string num1, num2, result;
		bool isMoveUp = false;
		
		cin >> num1 >> num2;
		string::reverse_iterator st1 = num1.rbegin();
		string::reverse_iterator st2 = num2.rbegin();
		while( st1 != num1.rend() || st2 != num2.rend()) {
			char buf1 = st1 != num1.rend() ? (*st1) : '0';
			char buf2 = st2 != num2.rend() ? (*st2) : '0';
			int buf3 = (buf1 - '0') + (buf2 - '0');
			
			isMoveUp = false;
			if(buf3 >= 10) {
				isMoveUp = true;
				(*(st1+1))++; buf3 -= 10;
			}
			result += (buf3 + '0');
			if(st1 != num1.rend()) { st1++; }
			if(st2 != num2.rend()) { st2++; }
		}
		if(isMoveUp) { result += '1'; }
		if(result.size() > 80) { cout << "overflou" << endl; continue; }
		string::reverse_iterator rt = result.rbegin();
		while(rt != result.rend()) {
			cout << (*rt);
			rt++;
		}
		cout << endl;
	}
	return 0;
}