#include<algorithm>
#include<cassert>
#include<climits>
#include<cmath>
#include<cstring>
#include<deque>
#include<functional>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

using lint = long long;
using P = pair<int, int>;
using LLP = pair<long long, long long>;

#define REP(i, x, n) for(int i = (x), i##_len = int(n) ; i < i##_len ; ++i)
#define rep(i, n) for(int i = 0, i##_len = int(n) ; i < i##_len ; ++i)
#define reps(i, n) for(int i = 1, i##_len = int(n) ; i <= i##_len ; ++i)
#define rrep(i, n) for(int i = int(n) - 1 ; i >= 0 ; --i)
#define rreps(i, n) for(int i = int(n) ; i > 0 ; --i)
#define SORT(x) sort((x).begin(), (x).end())
#define SORT_INV(x) sort((x).rbegin(), (x).rend())
#define TWINS(x) cout << ((x) ? "Yay!" : ":(") << endl

constexpr int IINF = (1 << 30) - 1;
constexpr long long LLINF = 1LL << 61;
constexpr double EPS = 1e-8;

const int dx4[] = {1, 0, -1, 0}, dy4[] = {0, 1, 0, -1};
const int dx8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dy8[] = {0, -1, -1, -1, 0, 1, 1, 1};

template<typename T>
bool chmax(T &a, T b){
    if(a < b){
        a = b;
        return true;
    }
    return false;
}

template<typename T>
bool chmin(T &a, T b){
    if(b < a){
        a = b;
        return true;
    }
    return false;
}

int f(int x){
    return x * x;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    while(n--){
        string s, t;
        cin >> s >> t;

        reverse(s.begin(), s.end());
        reverse(t.begin(), t.end());

        while(s.size() < t.size()){
            s.push_back('0');
        }
        while(t.size() < s.size()){
            t.push_back('0');
        }

        string ans = "";
        int k = 0;
        rep(i, s.size()){
            int tmp = s[i] - '0' + t[i] - '0' + k;
            ans.push_back((tmp % 10) + '0');
            k = tmp / 10;
        }
        if(k){
            ans.push_back(k + '0');
        }

        if((int)ans.size() <= 80){
            reverse(ans.begin(), ans.end());
            cout << ans << endl;
        }else{
            cout << "overflow" << endl;
        }
    }

    return 0;
}
