#include <iostream>
#include <string>
using namespace std;

string reserve(string a, int len)
{
    string rev = a;
    for (int i=0;i<len;i++)
    {
        rev[i] = a[len-i-1];
    }
    return rev;
}

int main()
{
    string a,b,d;
    int num;
    int cons;
    d = "";
    int tmp;
    cin >> num;
    while(num--)
    {
        cin >> a >> b;
        a = reserve(a,a.size());

        b = reserve(b,b.size());
        int maxi = max(a.size(),b.size());
        int mini = min(a.size(),b.size());
        d.resize(maxi+1);
        a.resize(maxi+1,0);
        b.resize(maxi+1,0);
        int c[maxi+1];
        int i;
        for(i=0;i<=maxi;i++)
        {
            c[i] = 0;
        }

        if(a.size() > 80 || b.size() > 80)
            cout << "overflow" << endl;
        else
        {
                for(int i=0 ;i <=maxi;i++)
                {
                    if(i<mini)
                        cons = 96;
                    else  if(i<maxi)
                        cons = 48;
                    else cons = 0;
                    tmp = a[i] + b[i] + c[i] - cons;
                    if (tmp > 9)
                    {
                        c[i+1] = 1;
                        tmp -= 10;

                    }
                    d[i] = tmp + 48 ;
                }

        }
        if(c[maxi]==1)
            d.resize(maxi+1);
        else d.resize(maxi);

        if(d.size() > 80)
            cout << "overflow" << endl;
        else
        {
            d = reserve(d,d.size());
            cout << d << endl;
        }

    }
    return 0;
}