#include <iostream>
#include <string>
// #include <algorithm>
using namespace std;

int main() {
  int tcase;
  
  cin >> tcase;
  while(tcase--) {
    string A, B, C = "";
    cin >> A >> B;
    
    unsigned sz = max(A.size(), B.size());
    while(A.size()<sz) A = '0' + A;
    while(B.size()<sz) B = '0' + B;

    int c = 0;
    for(int i=sz-1; i>=0; i--) {
      // 確定情報
      C += ( (A[i]-'0') + (B[i]-'0') + c ) % 10 + '0';
      // 前座
      c = ( (A[i]-'0') + (B[i]-'0') + c ) / 10;
    }
    if(c>0) C += ( (A[sz-1]-'0') + (B[sz-1]-'0') + c ) % 10 + '0';
    
    reverse(C.begin(), C.end());
    cout << C << endl;
  }
  return 0;
}