import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.LinkedHashMap;

public class Veronika {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        String line = reader.readLine();
        String distincted = getDistincted(line);

        LinkedHashMap<Character, Long> occurences = new LinkedHashMap<>();
        for (char ch : distincted.toCharArray()) {
            long currCnt = line.chars().filter(c -> c == ch).count();
            occurences.put(ch, currCnt);
        }

        System.out.println();
    }

    private static String getDistincted(String line) {
        StringBuilder sb = new StringBuilder();

        line.chars()
                .distinct()
                .forEach(ch -> sb.append((char) ch));

        return sb.toString();
    }
}