#include <iostream>
#include <fstream>
#include <string>
#include <queue>
using namespace std;

int main() {
    ifstream fin("data4.txt");
    if (!fin.is_open()) exit(0);
    
    ofstream fout("out4.txt");
    
	int i, j;
	
	int seen[26];

	
	for (int ncases=0; ncases<5; ncases++) {
		string input;
		fin >> input;
	
		for (i=0; i<26; i++) seen[i] = 0;
		for (i=0; i<input.length(); i++)
			seen[input[i] - 'A']++;
		for (i=0; i<input.length(); i++)
			if (seen[input[i] - 'A'] == 1) {
				fout << input[i] << endl;
				break;
			}
			
	}
	return 0;
}