import java.io.*;

public class Main {


    private static String createAcronimFromString(String input){
        StringBuilder outString = new StringBuilder();
        String[] afterSplit = input.split(" ");
        for(int i = 0; i < afterSplit.length; ++i){
            char ch = afterSplit[i].charAt(0);
            outString.append(Character.toLowerCase(ch));
        }
        return outString.toString();
    }

    private static void myFileReader(String fileName, String phrase){
        int counter = 0;
        File file = new File(fileName);
        BufferedReader bufferedReader = null;
        try {
            bufferedReader = new BufferedReader(new FileReader(file));
        }  catch (FileNotFoundException ex) {
            System.out.println(ex.toString());
        }
        String st;
        if(bufferedReader != null) {
            try {
                while ((st = bufferedReader.readLine()) != null) {
                    counter++;
                    if(counter % 2 == 0) {
                        if(st.contains(phrase)){
                            StringBuilder builder = new StringBuilder();
                            String strings[] = st.split(phrase);
                            for(int i = 0; i < strings.length; ++i){
                                if(strings[i].equals(phrase))
                                    strings[i].toUpperCase();
                            }
                            for(int i = 0; i < strings.length; ++i){
                                builder.append(strings[i]);
                            }
                            System.out.println(builder.toString()); // DYBAL WAZNE: JEZELI TUTAJ MASZ WYPISYWAC TO DO PLIKU TO TO ZROB BO POLECENIE JEST STRASZNIE NIE JASNE I TA FUNCKJA TBH CHUJOWA
                        }
                    } else {
                        for(int i = 0; i < st.length(); ++i){
                            if(Character.isUpperCase(st.charAt(i))){
                                StringBuilder builder = new StringBuilder(st);
                                builder.setCharAt(i, 'm');
                                st = builder.toString();
                            }
                        }
                        System.out.println(st); // TAK SAMO Z TYM PLIKIEM JAK WYZEJ KOMENTARZ
                    }
                }
            } catch (IOException ex){
                ex.printStackTrace();
            }
        }

    }

    public static void main(String[] args) {
        String string = "test string xd";
        System.out.println(createAcronimFromString(string));
    }
}