#include <iostream>
#include <cstdlib>
#include <stdint.h>
#include <cmath>
using namespace std;

int getNumberOfDigits(int64_t i)
{
    return i > 0 ? (int) log10(((double) i)) + 1 : 1;
}

int main()
{
    int iN;
    cin >> iN;
    int64_t sum, iA, iB;
    for(int c = 0; c < iN; c++)
    {
        cin >> iA;
        cin >> iB;
        sum = iA + iB;
        if(getNumberOfDigits(sum) > 80)
            cout << "overflow" << endl;
        else
            cout << sum << endl;
    }
    return EXIT_SUCCESS;
}