#include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <utility>
#include <cstring>
#include <iomanip>
#include <numeric>
#include <cmath>
#include <queue>
#include <map>
using namespace std;
typedef long long ll;
const int INF = 1<<30; 
const int MOD = 1e9 + 7;
const int dy[] = {1, 0, -1, 0};
const int dx[] = {0, 1, 0, -1};
int to_int(char ch){ return ch - '0'; }
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    string s, t;
    int n;
    cin >> n;
    while(n--)
    {
        cin >> s >> t;
        if(s.size() < t.size()) swap(s, t);
        reverse(s.begin(), s.end());
        reverse(t.begin(), t.end());
        int up = 0;
        for(int i = 0; i < t.size(); i++)
        {
            int val = to_int(s[i]) + to_int(t[i]) + up;
            if(val > 9)
            {
                val -= 10;
                s[i] = val + '0'; 
                up = 1;
            }
            else
            {
                s[i] = val + '0';
                up = 0;
            }
        }
        int pos = t.size();
        while(up)
        {
            if(pos >= s.size()) break;
            if(to_int(s[pos]) + up > 9) s[pos] = '0';
            else up = 0;
            pos++;
        }
        if(up) s += '1';
        reverse(s.begin(), s.end());
        if(s.size() > 80) cout << "overflow" << endl;
        else cout << s << endl;
    }
    return 0;
}
