#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define ALL(x) (x).begin(), (x).end()
#ifdef LOCAL
#include "debug.hpp"
#else
#define debug(...) void(0)
#endif

template <typename T> istream& operator>>(istream& is, vector<T>& v) {
    for (T& x : v) is >> x;
    return is;
}
template <typename T> ostream& operator<<(ostream& os, const vector<T>& v) {
    for (size_t i = 0; i < v.size(); i++) {
        os << v[i] << (i + 1 == v.size() ? "" : " ");
    }
    return os;
}

template <typename T> T gcd(T x, T y) { return y != 0 ? gcd(y, x % y) : x; }
template <typename T> T lcm(T x, T y) { return x / gcd(x, y) * y; }

int topbit(signed t) { return t == 0 ? -1 : 31 - __builtin_clz(t); }
int topbit(long long t) { return t == 0 ? -1 : 63 - __builtin_clzll(t); }
int botbit(signed a) { return a == 0 ? 32 : __builtin_ctz(a); }
int botbit(long long a) { return a == 0 ? 64 : __builtin_ctzll(a); }
int popcount(signed t) { return __builtin_popcount(t); }
int popcount(long long t) { return __builtin_popcountll(t); }
bool ispow2(int i) { return i && (i & -i) == i; }
long long MSK(int n) { return (1LL << n) - 1; }

template <class T> T ceil(T x, T y) {
    assert(y >= 1);
    return (x > 0 ? (x + y - 1) / y : x / y);
}
template <class T> T floor(T x, T y) {
    assert(y >= 1);
    return (x > 0 ? x / y : (x - y + 1) / y);
}

template <class T1, class T2> inline bool chmin(T1& a, T2 b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T1, class T2> inline bool chmax(T1& a, T2 b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template <typename T> void mkuni(vector<T>& v) {
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
}
template <typename T> int lwb(const vector<T>& v, const T& x) { return lower_bound(v.begin(), v.end(), x) - v.begin(); }

const int INF = (1 << 30) - 1;
const long long IINF = (1LL << 60) - 1;
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const int MOD = 998244353;
// const int MOD = 1000000007;

#include <cassert>
#include <chrono>
#include <random>
#include <string>
#include <vector>

struct RollingHash {
    static inline uint64_t generate_base() {
        std::mt19937_64 mt(std::chrono::steady_clock::now().time_since_epoch().count());
        std::uniform_int_distribution<uint64_t> rand(2, RollingHash::mod - 1);
        return rand(mt);
    }

    RollingHash(uint64_t base = generate_base()) : base(base), power{1} {}

    template <typename T> std::vector<uint64_t> build(const T& s) const {
        int n = s.size();
        std::vector<uint64_t> hash(n + 1);
        hash[0] = 0;
        for (int i = 0; i < n; i++) hash[i + 1] = add(mul(hash[i], base), s[i]);
        return hash;
    }

    template <typename T> uint64_t get(const T& s) const {
        uint64_t res = 0;
        for (const auto& x : s) res = add(mul(res, base), x);
        return res;
    }

    uint64_t query(const std::vector<uint64_t>& hash, int l, int r) {
        assert(0 <= l && l <= r);
        extend(r - l);
        return add(hash[r], mod - mul(hash[l], power[r - l]));
    }

    uint64_t combine(uint64_t h1, uint64_t h2, size_t h2_len) {
        extend(h2_len);
        return add(mul(h1, power[h2_len]), h2);
    }

    int lcp(const std::vector<uint64_t>& a, int l1, int r1, const std::vector<uint64_t>& b, int l2, int r2) {
        int len = std::min(r1 - l1, r2 - l2);
        int lb = 0, ub = len + 1;
        while (ub - lb > 1) {
            int mid = (lb + ub) >> 1;
            (query(a, l1, l1 + mid) == query(b, l2, l2 + mid) ? lb : ub) = mid;
        }
        return lb;
    }

private:
    static constexpr uint64_t mod = (1ULL << 61) - 1;
    const uint64_t base;
    std::vector<uint64_t> power;

    static inline uint64_t add(uint64_t a, uint64_t b) {
        if ((a += b) >= mod) a -= mod;
        return a;
    }

    static inline uint64_t mul(uint64_t a, uint64_t b) {
        __uint128_t c = (__uint128_t)a * b;
        return add(c >> 61, c & mod);
    }

    inline void extend(size_t len) {
        if (power.size() > len) return;
        size_t pre = power.size();
        power.resize(len + 1);
        for (size_t i = pre - 1; i < len; i++) power[i + 1] = mul(power[i], base);
    }
};

void solve() {
    string S;
    cin >> S;

    int n = S.size();
    RollingHash rh;
    auto hash = rh.build(S);
    int L = -1, LEN = 0;
    for (int len = 1; len <= n; len++) {
        map<uint64_t, int> mp;
        for (int i = 0; i + len <= n; i++) {
            if (i - len >= 0) mp[rh.query(hash, i - len, i)] = i - len;
            auto x = rh.query(hash, i, i + len);
            if (mp.count(x) and (LEN < len or mp[x] < L)) L = mp[x], LEN = len;
        }
    }
    string ans = S.substr(L, LEN);

    cout << ans << '\n';
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int T;
    cin >> T;
    for (; T--;) solve();
    return 0;
}