#include<iostream>
#include<cstring>
using namespace std;
int main(){
	int n;
	cin >>n;
	for(int i=0; i<n; i++){
		char num[2][900];
		int ans[900],up=0,t,l;
		cin >>num[0]>>num[1];
		int a = strlen(num[0]), b = strlen(num[1]), max = (b>a)? b:a, min = (b>a)? a:b;
		for(l=0; l<max; l++){
			if(l<min){t = (int)num[0][a-l-1]+(int)num[1][b-l-1]-48*2+up;}
			else if(a<b){t = (int)num[1][b-l-1]-48+up;}
			else{t = (int)num[0][a-l-1]-48+up;}
			if(t>9){t-=10;up = 1;}
			else{up = 0;}
			ans[l] = t;
		}
		if(up == 1){ans[max] = 1;l++;}
		if(l<=80)for(int m=l-1; m>=0; m--){cout <<ans[m];}
		else{cout<<"overflow";}
		cout <<endl;
	}
	return 0;
}