#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

const int N = 110;
string s[N][N]; int n;

int cnt(int l, int r) {
    for (int i = 2 * r - l + 1; i <= n; ++i) if (s[i - r + l][i] == s[l][r]) return 2;
    return 1;
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    if (fopen("qoj_5666.inp", "r")) {
        freopen("qoj_5666.inp", "r", stdin);
        freopen("qoj_5666.out", "w", stdout);
    }

    #ifdef LOCAL_MACHINE 
        if (fopen("task.inp", "r")) {
            freopen("task.inp", "r", stdin);
            freopen("task.out", "w", stdout);
        }
    #endif

    int nTest; cin >> nTest;
    while(nTest--) {
        string st; cin >> st;
        n = st.size(); st = ' ' + st;
        for (int i = 1; i <= n; ++i) {
            s[i][i] = st[i];
            for (int j = i + 1; j <= n; ++j) s[i][j] = s[i][j - 1] + st[j];
        }

        string res = "";
        for (int len = n; len; --len) for (int l = 1; l <= n - len + 1; ++l) if (res.size() == 0 && cnt(l, l + len - 1) > 1) res = s[l][l + len - 1]; 

        cout << res << "\n";
    }
}

// ඞඞඞඞඞ you sus