#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>

using namespace std;

const int MAX_INPUT = 1000000;
const int ARRAY_SIZE = 11;
const int MAX_LEN = 8;
char inputA[MAX_INPUT];
char inputB[MAX_INPUT];

void toBigInt(char *str, long *r) {
    int len = strlen(str);
    int endIndex = ARRAY_SIZE - (len / MAX_LEN) - 1;

    {
        int offset = 0;
        for (int i = 0; i < ARRAY_SIZE; ++i) {
            char temp[MAX_LEN + 1] = { 0 };
            int readLen = ((len - offset) < MAX_LEN) ? len - offset : MAX_LEN;
            char* start = str + len - offset - readLen;

            strncpy(temp, start, readLen);
            r[ARRAY_SIZE - i- 1] = (long)atoi(temp);
            offset += readLen;
        }
    }
}

int main() {
    int n = 0;
    scanf("%d", &n);

    for (int i = 0; i < n; ++i) {
        scanf("%s\n%s", &inputA, &inputB);
        long a[ARRAY_SIZE] = { 0 };
        long b[ARRAY_SIZE] = { 0 };
        long r[12] = { 0 };
        int lenA = 0;
        int lenB = 0;
        const int MAX_INPUT_LEN = 80;
        lenA = strlen(&inputA[0]);
        lenB = strlen(&inputB[0]);
        if ((MAX_INPUT_LEN < lenA) || (MAX_INPUT_LEN < lenB)) {
            printf("overflow\n");
            continue;
        }

        toBigInt(inputA, a);
        toBigInt(inputB, b);
        for (int i = 0; i < ARRAY_SIZE; ++i) {
            int curRIndex = 12 - i - 1;
            r[curRIndex] += a[ARRAY_SIZE - i - 1] + b[ARRAY_SIZE - i - 1];
            const int MAX = 99999999;
            if (MAX < r[curRIndex]) {
                r[curRIndex - 1] = r[curRIndex] / (MAX + 1);
                r[curRIndex] %= (MAX + 1);
            }
        }

        {
            bool started = false;
            bool noOutput = true;
            for (int i = 0; i < 12; ++i) {
                if (!started && (0 < r[i])) {
                    started = true;
                    printf("%d", r[i]);
                    noOutput = false;
                    continue;
                }

                if (started) {
                    long temp = (r[i] == 0) ? 1 : r[i];
                    for (int j = 0; temp * pow(10, j) < 10000000; ++j) {
                        printf("0");
                    }

                    printf("%d", r[i]);
                }
            }

            if (noOutput) {
                printf("0");
            }
        }
        printf("\n");

        for (int i = 0; i < MAX_INPUT; ++i) {
            inputA[i] = 0;
            inputB[i] = 0;
        }
    }

    return 0;
}