#include <bits/stdc++.h>
using namespace std;

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

int main(){
    int n;
    cin >> n;
    for(int p=0; p < n; p++){
        string ans;
        string s, t;
        cin >> s >> t;
        if(s.size() > t.size()) swap(s, t);


        int q = t.size()-s.size();
        for(int i=0; i < q; i++) s = "0" + s;

        int up = 0;
        for(int i=s.size()-1; 0 <= i; i--){
            int d = atoi(s.substr(i, 1).c_str());
            int f = atoi(t.substr(i, 1).c_str());
            ans = IntToString((d+f+up)%10) + ans;

            if(0 <= d+f+up-10) up = 1;
            else up = 0;
        }
        if(up == 1) ans = IntToString(1) + ans;

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