#include <iostream>
#include <algorithm>
using namespace std;
#define DEBUG(x) cerr << #x << ":" << x << endl;
int main(){
    int n;
    cin>>n;
    for(int i=0;i<n;++i){
        string a,b,c;
        int d=0,st;
        cin>>a>>b;
        for(int j=a.size();j<81;++j) a="0"+a;
        for(int j=b.size();j<81;++j) b="0"+b;
		// DEBUG(a);
		// DEBUG(b);
        reverse(a.begin(), a.end());
        reverse(b.begin(), b.end());
        for(int j=0;j<80;++j){
            c+=((a[j]-'0')+(b[j]-'0')+d)%10+'0';
            d=((a[j]-'0')+(b[j]-'0')+d)/10;
        }
        if(d>0) cout<<"overflow\n";
        else{
            reverse(c.begin(), c.end());
			/*
            for(st=0;st<c.size();++st)if(c[st]!='0')break;
            cout<<((st==c.size())?"0\n":c.substr(st,c.size()-st)+"\n");
			*/
			st = 0;
			while(c[st] == '0') st++;
			for(int j = st; j < c.size(); j++)
				cout << c[j];
			cout << endl;
        }
    }
    return 0;
}