#include<bits/stdc++.h>
#define int long long
#define endl '\n'
#define PII pair<int , int>
using namespace std;
const int N = 1e6 + 10;
int n , m ;
int mid = 1e9 + 7;

void matt(){
    string s , t;
    cin >> s >> t;
    map<char , set<int>>mp;
    for (int i = 0; i < s.size(); i++)
    {
        mp[s[i]].insert(i);
    }
    int i1 = 0 , j1 = 0 , maxx = N;
    for(auto x : mp[t[0]]){
        int j = x;
        int tr = 0;
        for (int i = 1; i < t.size(); i++)
        {
            int k;
            k = *mp[t[i]].upper_bound(j);
            if(k <= j){tr = 1; break;} 
            j = k;
        }
        if(tr) continue;
        if(j - x + 1 < maxx){
            i1 = x ;
            j1 = j ;
            maxx = j - x + 1;
        }
    }
    for (int i = i1; i <= j1; i++)
    {
        cout << s[i];
    }
    cout << endl;
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    cin >> T;
    while (T--)
    {
        matt();
    }
    return 0;
}