#include<iostream>
#include<string>
using namespace std;
int main(){
	int n;
	cin >>n;
	while(n--){
		string a, b, c;
		cin >>a>>b;
		int x = a.size(), y = b.size(), t = 0, max = (x>y)?x:y;
		for(int i=0; i<max; i++){
			if(i<x && i<y){t = (int)a[x-i-1]+(int)b[y-i-1]-2*'0'+t/10;}
			else if(i<x){t = (int)a[x-i-1]-'0'+t/10;}
			else if(i<y){t = (int)b[y-i-1]-'0'+t/10;}
			c+=(char)(t%10)+'0';
		}
		if(t/10){c+='1';}
		if(c.size() > 80){cout<<"overflow";}
		else{for(int i=c.size()-1; i>=0; i--){cout<<c[i];}}
		cout<<endl;
	}
	return 0;
}