#include<bits/stdc++.h>
using namespace std;
const int N = 101;
char a[N]; int b[N];
struct node{
    int st, ed; string val = "";
}t[N * N];
inline bool kkk(node x, node y){
    return x.val < y.val;
}
int main(){
    int T;
    scanf("%d", &T);
    while(T --){
        scanf("%s", a);
        int len = strlen(a), cnt = 0;
        for(int i = 0; i < len; ++i){
            string now = "";
            for(int j = i; j < len; ++j){
                now += a[j];
                t[++cnt].val = now; t[cnt].st = i, t[cnt].ed = j;
            }
        }
        sort(t + 1, t + cnt + 1, kkk);
        string ans = ""; int ans1 = -1;
        for(int i = 2; i <= cnt; ++i){
            if(t[i].val == t[i - 1].val){
                int l = i - 1, r = cnt;
                for(int j = i; j <= cnt; ++j){
                    if(t[j].val != t[i].val){
                        r = j - 1;
                        break;
                    }
                }
                i = r;
                int maxe = 0, ming = 2e9;
                for(int j = l; j <= r; ++j){
                    maxe = max(maxe, t[j].st);
                    ming = min(ming, t[j].st);
                }
                if(ming + t[l].val.size() - 1 < maxe){
                    if(t[l].val.size() > ans.size()){
                        ans = t[l].val, ans1 = ming;
                    }else if(t[l].val.size() == ans.size() && ans1 > ming){
                        ans = t[l].val, ans1 = ming;
                    }
                }
            }
        }
        cout << ans << '\n';
    }
    return 0;
}