#include <iostream>
#include <cstring>
#include <string>
#include <algorithm>

using namespace std;

int main(){
    int n; cin >> n;
    while(n--){
        string a,b;
        cin >> a >> b;
        reverse(a.begin(), a.end());
        reverse(b.begin(), b.end());
        if(b.size() < a.size()) swap(a,b);
        b += "0";
        for(int i=0; i<b.size()-1; i++){
            int aa = i < a.size() ? a[i] - '0' : 0;
            int bb = b[i] - '0';
            int cc = aa + bb;
            b[i] = (cc%10) + '0';
            //cout << aa << "+" << bb << "=" << cc << endl;
            if(cc >= 10){
                b[i+1]++;
            }
        }
        if(b[b.size()-1] == '0')
            b = string(b.begin(), b.end()-1);
        reverse(b.begin(), b.end());
        if(b.size() >= 80)
            cout << "overflow" << endl;
        else cout << b << endl;
    }
    return 0;
}
    