#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, const char * argv[]) {
    int a[80];
    int b[80];
    char temp[80];
    int x, y;
    int s[80];
    int a_num, b_num, n, i;

    scanf("%d", &y);
    for (i=0; i<y; i++) {
        for (n = 0; n < 80; n++) {
            a[n] = 0;
            b[n] = 0;
            s[n] = 0;
        }
        
        a_num = 0;
        scanf("%s", temp);
        a_num = (int)strlen(temp) - 1;
        for (n = 0; n <= a_num; n++){
            a[a_num - n] = temp[n] - 48;
        }

        b_num = 0;
        scanf("%s", temp);
        b_num = (int)strlen(temp) - 1;
        for (n = 0; n <= b_num; n++) {
            b[b_num - n] = temp[n] - 48;
        }
        
        if (a_num > 80 || b_num > 80) {
            printf("overflow\n");
        } else {
            if (a_num >= b_num) {
                for (n=0; n <= a_num; n++) {
                    x = a[n] + b[n] + s[n];
                    if (x > 9) {
                        s[n+1]++;
                        x = x - 10;
                    }
                    s[n] = x;
                }
                if (s[a_num+1] > 0) printf("%d", s[a_num+1]);
                for (n=a_num; n >= 0; n--) {
                    printf("%d", s[n]);
                }
                printf("\n");
            } else {
                for (n=0; n <= b_num; n++) {
                    if ((x = a[n] + b[n] + s[n]) > 9) {
                        s[n+1]++;
                        x = x - 10;
                    }
                    s[n] = x;
                }
                if (s[b_num+1] > 0) printf("%d", s[b_num+1]);
                for (n=b_num; n >= 0; n--) {
                    printf("%d", s[n]);
                }
                printf("\n");
            }
        }
    }
    return 0;
}