#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

int get(char c)
{
	if ('a' <= c && c <= 'z')
		return c - 'a';
	return c - '0' + 26;
}

void solve()
{
	string s, t;
	cin >> s >> t;
	int n = SZ(s);
	vector<VI> nxt(n + 1, VI(36, n));
	RFOR (i, n, 0)
	{
		nxt[i] = nxt[i + 1];
		nxt[i][get(s[i])] = i;
	}
	PII ans = {n, 0};
	FOR (i, 0, n)
	{
		if (s[i] != t[0])
			continue;
		int k = i;
		int j = 1;
		while (k < n && j < SZ(t))
		{
			k = nxt[k + 1][get(t[j])];
			j++;
		}
		if (k != n)
			ans = min(ans, {k - i + 1, i});
		else
			break;
	}
	cout << s.substr(ans.S, ans.F) << '\n';
	
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	int t;
	cin >> t;
	while (t--)
		solve();
	
	
	return 0;
}