#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(void)
{
    char num1[81],num2[81];
        int a1[81],a2[81],ans[81];
        int i,j,n,k,l1,l2,kuriagari=0;
        scanf("%d",&n);
        for(i=0;i<n;i++)
        {
                for(j=0;j<81;j++)
                {
                        a1[j] = 0;
                        a2[j] = 0;
                        ans[j] = 0;
                }
                scanf("%s",num1);
                scanf("%s",num2);
                l1 = strlen(num1);
                l2 = strlen(num2);
                for(j=0;j<l1;j++)
                {
                        a1[j] = num1[l1-1-j] - '0';
                }
                for(j=0;j<l2;j++)
                {
                        a2[j] = num2[l2-1-j] - '0';
                }
                for(j=0;j<81;j++)
                {
                        ans[j] = (a1[j] + a2[j] + kuriagari) % 10;
                        kuriagari = (a1[j] + a2[j] + kuriagari)/10;
                }
                if(ans[80] != 0)
                {
                        printf("overflow\n");
                }
                else
                {
                        for(j=80;j>=0;j--)
                        {
                                if(ans[j] != 0)
                                {
                                        k = j;
                                        break;
                                }
                        }
                        for(j=k;j>=0;j--)
                        {
                                printf("%d",ans[j]);
                        }
                        printf("\n");
                }
        }
        return 0;
}