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

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pii;
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)x.size();
#define rep(i,j,k) for (int i = j; i < (k); i++)
#define in(mp, v) (mp.find(v) != mp.end())
#define smx(a, b) a = max(a, b)
#define smn(a, b) a = min(a, b)
#define pb push_back
#define endl '\n'

const ll MOD = 1e9 + 7;
const ld EPS = 1e-9;

void solve() {
    string s; cin >> s;
    int n = s.size();
    for (int len = n - 1; len >= 1; len--) {
        map<string, vector<int>> pos;
        for (int i = 0; i + len <= n; i++) {
            pos[s.substr(i, len)].push_back(i);
        }
        int minOcc = 1000;
        // string t;
        for (auto& [k, v] : pos) {
            if (v.size() == 1) continue;
            for (int i = 0; i < v.size() - 1; i++) {
                if (v[i + 1] >= v[i] + len) {
                    if (v[i] < minOcc) {
                        minOcc = v[i];
                        // t = k;
                    }
                }
            }
        }
        if (minOcc < 1000) {
            cout << s.substr(minOcc, len) << "\n";
            return;
        }
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    int t; cin >> t;
    while (t--) {
        solve();
            
    }
}