import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.Map;
import java.util.HashMap;

public class Main {
	
	private static Scanner sc;
	
	private static void process() {
		// TODO Auto-generated method stub
		Map<String,Integer[]> M = new HashMap<String,Integer[]>();
		String s = sc.next();
		int n = s.length();
		for(int i=0;i<n;i++) {
			for(int j=i;j<n;j++) {
				String sub = s.substring(i,j+1);
				if(!M.containsKey(sub)) {
					M.put(sub,new Integer[] {i,-1});
				} else if(M.get(sub)[0]+sub.length()<=i) {
					M.get(sub)[1] = i;
				}
			}
		}
		
		int index = -1;
		String ret = "";
		for(String key : M.keySet()) {
			if(M.get(key)[1] != -1) {
				if(ret.length() < key.length() || ret.length() == key.length() && index > M.get(key)[0]) {
					ret = key;
					index = M.get(key)[0];
				}
			}
		}
		
		System.out.println(ret);
	}

	public static void main(String[] args) throws FileNotFoundException {
		// TODO Auto-generated method stub
		sc = new Scanner(System.in);
		int T = sc.nextInt();
		for(int i=0;i<T;i++) {
			process();
		}
	}	

}