#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <sstream>
#include <string>
using namespace std;

string IntToString(int number)
{
    stringstream ss;
    ss << number;
    return ss.str();
}

int main(){
    int n;
    cin >> n;
    for(int i=0; i < n; i++){
        string ans;
        string p, q;
        cin >> p >> q;
        if(p.size() < q.size()) swap(p, q);
        int diff = p.size()-q.size();
        for(int i=0; i < diff; i++){
            q = '0' + q;
        }
        p = '0' + p; q = '0' + q;
        int up = 0;
        for(int i=p.size()-1; 0 <= i || up != 0; i--){
            int m = atoi(p.substr(i,1).c_str()) + atoi(q.substr(i, 1).c_str());
            ans = IntToString((m+up)%10) + ans;
            up = (m+up)/10;
        }
        if(ans[0] == '0') ans = ans.substr(1, ans.size()-1);

        if(80 < ans.size()) cout << "overflow" << endl;
        else cout << ans << endl;
    }
}