#include <iostream>

int main()
{
        char a[1000], b[1000];
        int c[80], ca, cb, set, up = 0;
        std::cin >> set;

        for(int i = 0; i < set; ++i)
        {
                for(int j = 0; j < 80; ++j)
                        c[j] = 0;
                up = ca = cb = 0;
                std::cin >> a >> b;

                for(int j = 0; j < 1000; ++j)
                        if((a[j] - '0' < 0) || (a[j] - '0' > 9))
                        {
                                ca = j - 1;
                                break;
                        }

                if(ca > 79)
                {
                        std::cout << "overflow" << std::endl;
                        continue;
                }

                for(int j = 0; j < 1000; ++j)
                        if((b[j] - '0' < 0) || (b[j] - '0' > 9))
                        {
                                cb = j - 1;
                                break;
                        }

                if(cb > 79)
                {
                        std::cout << "overflow" << std::endl;
                        continue;
                }
                for(int j = 0; j < 80; ++j)
                {
                        if(ca < j && cb < j)
                        {
                                c[j] = up % 10;
                                up = up / 10;
                        }
                        else if(ca < j)
                        {
                                c[j] = (b[cb - j] - '0' + up) % 10;
                                up = (b[cb - j] - '0' +up) / 10;
                        }
                        else if(cb < j)
                        {
                                c[j] = (a[ca - j] - '0' + up) % 10;
                                up = (a[ca - j] - '0' +up) / 10;
                        }
                        else
                        {
                                c[j] = (a[ca - j] - '0' + b[cb - j] - '0' + up) % 10;
                                up = (a[ca -j] - '0' + b[cb - j] - '0' +up) / 10;
                        }
                }

                if(up > 0)
                {
                        std::cout << "overflow" << std::endl;
                        continue;
                }

                int k = 0;
                for(int j = 0; j < 80; ++j)
                        if(c[79 - j])
                        {
                                k = j;
                                break;
                        }

                if(k)
                        for(int j = k; j < 80; ++j)
                                std::cout << c[79 - j];
                else
                        std::cout << 0;
                std::cout << std::endl;
        }
        return 0;
}