#include<iostream>
#include<cstdio>
#include<map>
#include<algorithm>
#include<string>
#include<set>
#include<string.h>
#include<queue>
using namespace std;
struct node
{
    int l, r;
    char val;
};
node tree[10010];
int idx;
map<char, int> ha;
string a, b;
int build(int pl, int pr, int il, int ir)
{
    int t = ++idx;
    if (pl > pr)
    {
        tree[t].val = '0';
        return 0;
    }
    int cur = ha[a[pl]];
    int l = build(pl + 1, pl + cur - il, il, cur - 1);
    int r = build(pl + cur - il + 1, pr, cur + 1, pr);

    tree[t].l = l;
    tree[t].r = r;
    tree[t].val = a[pl];
    return t;

}
void dfs(int root)
{
    queue<int > q;
    q.push(root);
    while (q.size())
    {
        int top = q.front();
        q.pop();
        cout << tree[top].val;
        if (tree[top].l)
            q.push(tree[top].l);
        if (tree[top].r)
            q.push(tree[top].r);
    }
}
int main()
{
    int T;
    cin >> T;
    while (T--)
    { 
        cin >> a >> b;
        ha.clear();
        idx = 0;
        for (int i = 0; i < b.size(); i++) ha[b[i]] = i;
        int root = build(0, a.size() - 1, 0, b.size() - 1);
        dfs(root);
        cout << endl;
    }
    return 0;
}

//递归建立二叉树的函数