#include <iostream>
#include <cstdio>
#include <vector>
#include <list>
#include <algorithm>
#include <cmath>
#include <stack>
#include <set>
using namespace std;

#define REP(i,n) for(int (i)=0; (i)<(n); (i)++)
#define FOR(i,a,b) for(int (i)=(a); (i)<(b); (i)++)
#define PUSH(n,v) for(int i=0; i<(n); i++) {int j; cin >> j; v.push_back(j);}
#define ALL(v) v.begin(), v.end()

int getdigit2(long long a) {
    if (a == 0) return 1;
    int cnt = 0;
    while(a) {
        cnt++;
        a /= 10;
    }
    return cnt;
}


int main() {
    long long a, b;
    int n;
    cin >> n;
    REP(i,n) {
        cin >> a >> b;
        if (getdigit2(a) > 80 || getdigit2(b) > 80 || getdigit2(a + b) > 80) cout << "overflow" << endl;
        else {
            cout << a + b << endl;
        }
    }
    return 0;
}