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

FILE *fin = fopen("bai3.inp", "r"), *fout = fopen("bai3.out", "w");

char sum(char a[], char b[], char c[]);
void format_number(char a[], char b[]);

int main(){
    int n;
    fscanf(fin, "%d", &n);
    char a[256], b[256], c[256];
    while(n--){
        fscanf(fin, "%s", &a);
        fscanf(fin, "%s", &b);
        printf("a = %s, b = %s\n", a, b);
        sum(a, b, c);
        fprintf(fout, "%s\n", c);
        printf("c = %s\n", c);
    }
    fclose(fin);
    fclose(fout);
}

char sum(char a[], char b[], char c[]){
    strrev(a);                                                          //dao nguoc 2 so lai
    strrev(b);
    int len;
    if(strlen(a) > strlen(b)){
        len = strlen(a) + 1;
        format_number(a, b);                                            //ham nay dung de them so 0 vao so it chu so hon, vi du 1234 vs 12 thi se chuyen thanh 12340 vs 12000
    }
    else{
        len = strlen(b) + 1;
        format_number(b, a);
    }
    int i, t = 0;
    int numa, numb;
    for(i = 0; i < len; i++){                                           //cong. cac' so' theo tung` hang`
        numa = a[i] - '0';
        numb = b[i] - '0';
        c[i] = (numa + numb + t)%10 + '0';
        t = numa + numb + t>= 10 ? 1 : 0;                               //t la` so' nho, vi du 9+6 thi viet 5 nho 1
    }
    c[len] = '\0';
    for(i = len-1; i > 0; i--){                                         //xoa so 0 thua
        if(c[i] == '0'){
            c[i] = '\0';
        }
        else
            break;
    }
    strrev(c);
}

void format_number(char a[], char b[]){
    int lena = strlen(a), lenb = strlen(b);
    a[lena] = '0';
    for(int i = lenb; i <= lena; i++)
        b[i] = '0';
}