#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int main(void){
	int n;

	cin >> n;
	while(n--){
		int len,big;
		string val[2];
		bool crr=false;

		for(int j=0;j<2;j++){
			cin >> val[j];
			reverse(val[j].begin(),val[j].end());
		}

		big=val[0].size()>=val[1].size()?0:1;
		val[1-big].append((len=val[big].size())-val[1-big].size(),'0');

		if(len<=80){
			for(int j=0;j<len;j++){
				val[0][j]+=val[1][j]+crr-0x60;
				crr=val[0][j]/10;
				val[0][j]%=10;
				val[0][j]+=0x30;
			}

			if(crr){
				val[0].append(1,'1');
				len++;
			}
		}

		if(len<=80)
			reverse(val[0].begin(),val[0].end());
		else
			val[0]="overflow";

		cout << val[0] << endl;
	}

	return 0;
}