#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>
#include <stack>

using namespace std;

int main (int argc, char * const argv[]) {
    // insert code here...
	int n;
    string a, b;
		
	cin>> n;	
	for(int i=0;i<n;i++){
		int x[81]={0}, y[81]={0};

		cin >> a;
		cin >> b;
		
		reverse(a.begin(), a.end());
		reverse(b.begin(), b.end());
		
		for(int j=0;j<a.size();j++){
			x[j]=a[j]-'0';
		}
		for(int j=0;j<b.size();j++){
			y[j]=b[j]-'0';
		}
		
		for(int j=0;j<80;j++){
			x[j]=x[j]+y[j];
			if(x[j]>=10){
				x[j+1]++;
				x[j]-=10;
			}
		}
		//cout << 0 << endl;
		
		if(x[80]>0){
			cout << "overflow" <<endl;
		}else{
			bool flag = 0;
			for(int j=79;j>=0;j--){
				if(x[j]==0&& flag==0){
					continue;
				}else{
					flag=1;
				}
				cout<<x[j];
			}
			cout<<endl;
		}
		
	}
	
	return 0;
}