#include <cstdio>
#include <bitset>
#include <cmath>
#include <complex>
#include <vector>
#include <algorithm>
#include <stack>

#define EPS 1e-6

using namespace std;
typedef complex<double> coor;

double cross(coor a, coor b)
{
  return a.real() * b.imag() - a.imag() * b.real();
}

double dot(coor a, coor b)
{
  return a.real() * b.real() + a.imag() * b.imag();
}

int main()
{
  int N;
  scanf(" %d ", &N);
  for (int i = 0; i < N; i++) {
    long long a, b;
    scanf(" %lld %lld ", &a, &b);
    if ((a + b) / 1e79 != 0) {
      printf("overflow\n");
      goto next;
    }
    printf("%lld\n", a + b);
  next:;
  }
  return 0;
}