#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <complex>
#include <string>
#include <sstream>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <functional>
#include <iostream>
#include <map>
#include <set>
using namespace std;
typedef pair<int,int> P;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-9
#define INF 2000000000
#define sz(x) ((int)(x).size())
#define fi first
#define sec second
#define SORT(x) sort((x).begin(),(x).end())
#define all(x) (x).begin(),(x).end()
#define EQ(a,b) (abs((a)-(b))<EPS)
int main()
{
	int n;
	cin >> n;
	for(int j=0;j<n;j++)
	{
		string s1,s2;
		vector<int> ans;
		cin >> s1;
		cin >> s2;
		reverse(s1.begin(),s1.end());
		reverse(s2.begin(),s2.end());
		int k=0;
		int p=max(s1.size(),s2.size());
		int len1=s1.size(),len2=s2.size();
		s1.resize(p+2);
		s2.resize(p+2);
		for(int i=len1;i<p+2;i++)
		{
			s1[i]='0';
		}
		for(int i=len2;i<p+2;i++)
		{
			s2[i]='0';
		}
		ans.resize(p+2);
		for(int i=0;i<p+2;i++)
		{
			ans[i]=((s1[i]-'0')+(s2[i]-'0')+k)%10;
			if((s1[i]-'0')+(s2[i]-'0')+k>=10)k=1;
			else k=0;
		}
		vector<int>::iterator it=ans.end();
		it--;
		int r=0;
		while(*it==0)
		{
			ans.erase(it);
			r++;
			it--;
		}
		ans.resize(p+2-r);
		reverse(ans.begin(),ans.end());
		for(int i=0;i<ans.size();i++)
		{
			cout << ans[i];
		}
		cout << endl;
	}
	return 0;
}