#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include<deque>
#include<map>
#include<set>
#include<string>
#include<sstream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<cctype>
#include<climits>
using namespace std;
#define REP(i, j) for(int i = 0; i < j; i++)
#define FOR(i, j, k) for(int i = j; i < k; i++)
#define P pair<int, int>
const int INF = INT_MAX / 2;
const int N = 80;

vector<int> makeDx(string str){
    reverse(str.begin(), str.end());
    vector<int> ret(N, 0);
    REP(i, str.size()) ret[i] = str[i] - '0';
    return ret;
}

int main(){
    int n; cin >>n;
    REP(z, n){
        string str[2]; cin >>str[0] >>str[1];
        vector<int> dx[2] = {makeDx(str[0]), makeDx(str[1])};
        vector<int> ans(N, 0);
        bool okflg = true;
        REP(i, N){
            int sum = dx[0][i] + dx[1][i];
            ans[i] += sum;
            if(i == N - 1 && ans[i] >= 10){
                cout <<"overflow" <<endl;
                okflg = false;
            }else if(ans[i] >= 10){
                ans[i + 1] = ans[i] / 10;
                ans[i] %= 10;
            }
        }
        if(okflg){
            reverse(ans.begin(), ans.end());
            int s = 0;
            while(ans[s] == 0 && s < N - 1) s++;
            FOR(i, s, N) cout <<ans[i];
            cout <<endl;
        }
    }
    return 0;
}