#include <iostream>
#include <cstdio>
#include <string>

using namespace std;

int main(){
	int n, c, res;
	bool f;
	string opr[2], buf;
	cin >> n;
	for(int i = 0;i < n;++i){
		c = 0;
		f = false;
		for(int j = 0;j < 2;++j){
			cin >> buf;
			if(buf.length() > 80) break;
			for(int k = 0;k < buf.length();++k) buf[k] = buf[k] - '0';
			opr[j].clear();
			for(int k = 0;k < 80 - buf.length();++k) opr[j] += (char)(0);
			opr[j] += buf;
		}
		if(buf.length() > 80){
			cout << "overflow" << endl;
			continue;
		}
		for(int j = opr[0].length() - 1;0 <= j;--j){
			res = opr[0][j] + opr[1][j] + c;
			opr[0][j] = res % 10;
			c = res / 10;
		}
		if(!c){
			for(int j = 0;j < opr[0].length();++j){
				if(!f) f = opr[0][j] != 0;
				if(f) cout << (char)(opr[0][j] + '0');
			}
		}
		else cout << "overflow";
		cout << endl;
	}
}