public class Solution {
    public static void main(String[] args) {
        BufferedReader reader = null;
        String temp;
        ArrayList<Visitor> visitors = new ArrayList<>();
        String [] tempForTime;

        try {
            reader = new BufferedReader(new FileReader("C:\\task2_inputData.txt"));

            while (reader.ready()) { //читаем файл
                temp = reader.readLine();
                temp = temp.substring(0, temp.length() - 2);
                tempForTime = temp.split(" ");
                DateFormat timeFormat = new SimpleDateFormat("HH:mm");
                Date tDuration = timeFormat.parse(tempForTime[0]);
              long  in = tDuration.getTime();
                tDuration = timeFormat.parse(tempForTime[1]);
                long out = tDuration.getTime();
                visitors.add(new Visitor(in,out));

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

        System.out.println(new Max().count(visitors).getOut());
    }
        public static class Max {

            private int max;//максимум посетителей
            private long in;//начало максимального посещения
            private long out;//конец максимального посещения

            public int getMax() {
                return max;
            }

            public long getIn() {
                return in;
            }

            public long getOut() {
                return out;
            }

          public Max count(List<Visitor> visitors) {
                Max maxVisitor = new Max();

                Set<Long> times = fillTime(visitors);
                int count = 0;
                int max = 0;
                long timeIn = 0;
                long timeOut = 0;
                for (Long time : times) {
                    for (Visitor visitor : visitors) {
                        if (time >= visitor.getIn() && time <= visitor.getOut()) {
                            count++;
                        }
                    }
                    if (count > max) {
                        max = count;
                        timeIn = time;
                        timeOut = time;
                    }
                    if (count == max) {
                        timeOut = time;
                    }
                    count = 0;
                }

                this.in = timeIn;
                this.out = timeOut;
                this.max = max;

                return maxVisitor;
            }


            private Set<Long> fillTime(List<Visitor> list) {
                Set<Long> timeSet = new TreeSet<>();
                for (Visitor element : list) {
                    timeSet.add(element.getIn());
                    timeSet.add(element.getOut());
                }
                return timeSet;
            }

        }
        public static class Visitor {

            private long in;

            private long out;

            public Visitor(long in, long out) {
                this.in = in;
                this.out = out;
            }

            public long getIn() {
                return in;
            }

            public long getOut() {
                return out;
            }
        }
    }

//значения во входном файле
8:00 8:30\n
8:45 9:00\n
8:30 9:00\n
9:00 9:30\n
9:10 9:20\n