public class Solution {
    public static Map<String, Integer> resultMap = new HashMap<String, Integer>();

    public static void main(String[] args) throws IOException {

        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String filename;
        while (true) {
            if (!(filename = reader.readLine()).equals("exit")) {
                new ReadThread(filename).start();
            }
        }

    }

    public static class ReadThread extends Thread {
        String fileName;

        public ReadThread(String fileName) {
            this.fileName = fileName;
        }

        @Override
        public void run() {
            try {
                FileInputStream stream = new FileInputStream(this.fileName);
                TreeMap<Byte, Integer> treeMap = new TreeMap<>();

                byte[] arr = new byte[stream.available()];
                int count = 0;

                while (stream.available() > 0) {
                    stream.read(arr);
                }
                stream.close();

                for (int x = 0; x < arr.length; x++) {
                    for (int y = 0; y < arr.length; y++) {
                        if (arr[x] == arr[y]&& x!=y)
                            count++;
                    }
                    treeMap.put(arr[x], count);

                    count = 0;
                }

                for (Map.Entry<Byte, Integer> xx : treeMap.entrySet()) {
                    if (count < xx.getValue()) {
                        count = xx.getValue();
                    }
                }

                for (Map.Entry<Byte, Integer> entry : treeMap.entrySet()) {
                    if (count == entry.getValue()) {
                        resultMap.put(fileName, (int) entry.getKey());
                        break;
                    }
                }


            } catch (IOException e) {
                e.printStackTrace();
            }
        }


    }
}